FIELD BOTANY

BIOLOGY 221
Fall 2004

Lytton John Musselman

Call Number: 11525

6 October 2004
Collection
Schedule
Peat mosses
Mushrooms
Ferns and fern allies
Winter botany

Introduction

What will you learn in this course?

Basically, this is a course identifying plants and mushrooms where they grow. I have selected only a few groups so we can learn these organisms in more depth. This semester we will emphasize mushrooms (and other fleshy fungi), peat mosses, ferns, and trees. By the end of the course, you will feel confident in naming these organisms when you see them. Here is the official catalog description: BIOL 221. Field Botany. Lecture 2 hours; laboratory 4 hours; 4 credits. Prerequisites: BIOL 115N, 116N. A study of the classification, identification and natural history of those organisms traditionally included in the study of botany. Laboratory techniques include field collection, preservation techniques, identification and the use and preparation of keys. This course satisfies the department botany course requirement.

This course may be much different from any other biology course you have taken because instruction will take place in the field! That means that we will have to examine, discuss, and take tests in the field. Because we are out-of-doors, it may not seem like a class experience. Remember, this IS your class time and in many cases we will have only one opportunity to view a mushroom or plant in flower.

1. My chief objective is to train you in how to learn plants. This is much different from just being able to name plants although naming is one of the end results of the process. A major emphasis here is on careful observation.

2. To develop critical techniques of observation and description.

3. Gain an understanding of the ecology of plants.

Because you have had general biology, I assume you know

• Basic terms applied to plant reproduction including: meiosis (and how it differs from mitosis), asexual reproduction, diploid, haploid, gametophyte, sporophyte, zygote, embryo, seed, fruit, carpel, flower, pollen, pistil, ovule.
• Basic terms used to describe leaves and shoots including: opposite leaves, alternate leaves, whorled leaves, compound leaf, simple leaf, blade, petiole, shoot, stem, bud, herbaceous growth, woody growth, bark, secondary growth, lenticel.
• The life cycle and terms used to describe mosses. I do not expect you to know the detailed vegetative anatomy of mosses.
• The life cycle of a homosporus fern. We will study heterosporous ferns as well.
• The life cycle and terms used to describ the life cycle of a fleshy basidiomycete.

If you need help, refer to a general botany textbook. I highly recommend the text by Raven, Evert, and Eicchorn, BIOLOGY OF PLANTS.

1. Handout. Often, a species list will be provided you. All this information will also be on the web.

2. Identification manuals

3. Clipboard

4. Clippers or pruning shears or sharp knife

5. Hand lens

6. Plastic (not clear) and paper bags

7. Insect repellant

8. Sturdy shoes

9. Long pants

10. Old phone book (for pressing plants)

11. Paper (MUST be paper!) bags for mushrooms. I have a supply.

12. Plain white paper. Simple photocopy paper is fine for use for mushroom spore prints. It must not be lined.

13. An email account and access to the internet. You must activate your ODU email acccount in order to access Blackboard. Once you activate your account you can have your email forwarded to any other account.

Tentative Schedule

Week Date Field Trip/topic

1 31 August The science of "botany"; logistics, introduction to the Blackwater Ecologic Preserve;identifying Sphagnum spp. and mushrooms. READINGS: Arora 1-62, 888-898.

E 3 September Optional test in testing center in Gornto.

2 7 September Blackwater Ecologic Preserve

3 21 September Gornto lab--Assistance in preparing and loading web materials.

4 28 September Dismal Swamp

5 5 October Meherrin River and Merchant=s Millpond LONG TRIP (i.e., return by 830p)

6 12 October FALL BREAK

7 19 October Northwest River Park

8 26 October Meherrin River LONG TRIP

9 2 November First Landing State Park

10 9 November To be selected

CLASS DINNER Wednesday 10 November 1830h (tentative date)

11 16 November Winter Botany

12 23 November Winter Botany

13 30 November Collections due

14 7 December Field Exam

Field quizzes (Eleven quizzes, 50 points each, drop one; twelve quizzes if you opt for the optional quiz) 500

Field Exam 200

Collection 200

TOTAL POINTS: 1000

A 90-100 %

B 80-89%

C 70-79%

D 60-69%

F Below 60%

Registering for this course does not mean that we can control the weather! Field trips may need to be re-scheduled because of inclement weather or because of progression of the season. In other words, some plants may come into flower or be more available if the weather becomes warmer or colder. I may find it necessary to change the way I compute your final grade based on the overall background of the class and other factors. In no case will this involve more than 15% of the total final grade.

This is a highly interactive class and may be quite different from others you have taken. Please, do not hesitate to ask for help. We will be spending many hours together and will have ample opportunity to talk. However, this is not intended to replace individual help outside class.

By appointment. Please call 683 3595 to make an appointment.

You are expected to attend each class because it is impossible to make up field trips for any reason.

Grades are posted electronically on LEO. Grades for tests will be posted on Blackboard. It is against university policy to use social security numbers or to email grades.

My policy on cheating and other forms of academic dishonesty will follow the university's recently revised guidelines. However, the first step is direct discussions between the purported offender and myself.

Most safety concerns are common sense, ie, safe driving. But there are some special concerns in this class which are noted below. This is not an exhaustive list.

1. Vehicle safety. The same regards you should have in your personal vehicle apply here.

2. Insects, snakes. If you are hyperallergic to insect bites, please let me know. Always check yourself after a field trip for ticks and remove them immediately. It is virtually certain that we will encounter venomous snakes. Always look before you step! Local hospitals of any size carry anti-venom.

3. Mushrooms. We will collect mushrooms. But never, never eat an unknown mushroom! No one is required to eat any mushrooms.

4. Lightning. We will not have field trips if there is a possibility of lightning.

5. Other health concerns. Inform me if you are epileptic or diabetic so we will know how to deal with an emergency.

A Determining @ a plant means recognizing it and giving it a name. It is synonymous in many ways with identification. Please give some thought as to how you recognize organisms. It may seem esoteric but will ultimately aid you in putting a name on the hundreds of plants you will see if this course. The following are important.

1. Character states. This includes the physical aspects of the plant-morphology, color, smell, etc. What is the shape of the plant and its parts? A subset of this would be the process of contrast/comparison by which we consciously or unconsciously compare the plant with other plants we know and thus eliminate some names.

2. Habitat and associated species. This is perhaps the most subtle of the techniques we use and becomes of value only when we know the ecology of a particular region.

4. Other.

Arora, D. 1986. Mushrooms Demystified. Berkeley: Ten Speed Press. Outrageous is probably a good word to describe this valuable book. The author's humor comes out in places where you would expect technical terms and explanations. It remains the best single book to identify mushrooms in North America.

Little, E. L., Jr. 1980. Field Guide to Trees. Eastern Region. National Audubon Society. New York: Knopf. I selected this text because of its reasonable cost and the breadth of coverage.

The world wide web is in such a state of flux that it is impossible to list new sites as they appear. I recommend two excellent sites as course resources where you can find information on a vast array of plants, fungi, and algae. The first is Scott's Botanical Links. The second is Internet Directory for Botany.

There could be some overlap between the two sites.

FIELD QUIZZES

The emphasis of these quizzes will be on the recognition of organisms. You will need to know the scientific name, properly spelled, for each. There will be eleven worth 50 points each. One quiz will be dropped. In addition, there is an optional test which you can take on Friday 3 September. You will take the test in the Testing Center in Gornto Hall. For information on location, hours, and regulations go to the Learning Assessment Lab website .

This test will cover material from the introductory material in Arora, Lellinger, and McQueen (see schedule for pages). You can substitute this test for one of the field tests.

COLLECTIONS

You will prepare collections of mushrooms and peat mosses. These will be turned in at the end of the course with each specimen properly labeled. It is not yet possible to say how many of each organism you will need because the abundance of mushrooms will depend on the weather. Collections will be returned to you but will be disposed of if not claimed by the end of the semester.

For mushrooms and peat mosses, turn in your collection in paper bags. We have a supply of these. Turn in your tree and fern specimens taped to paper. Remember, the purpose of the collection is to learn the plants. I do not want you to expend unnecessary time and expense on this.

20 mushrooms

25 trees of which 8 must be from the genus Quercus, and 3 from the genus Carya.

Depending on the weather, you will also need ten trees in winter condition.

STUDENT INFORMATION FORM--Due 31 AUGUST!! Print this form and either email it or put it in my mail box in MGB 110.

YOUR NAME: STUDENT NUMBER:

I. Number of credit hours in biology.

II. Expected year and semester of graduation.

III. Chief reason for taking general botany.

IV. Previous botany/plant courses (if any).

We will be collecting mushrooms. Some of these are edible and delicious. But you are not required to eat any mushrooms! If you do, it is by your choice. Never eat an unknown mushroom. Never assume, without careful determination, that mushrooms growing together are the same species. Bear in mind that some people are allergic to mushrooms; this is different than poisoning but can still be serious.

I understand that ingesting mushrooms can be dangerous and that careful determination and verification are essential before eating mushrooms.

YOUR NAME__________________________ SIGNATURE________________________________

DATE____________________

Following are outlines for studies of peat mosses, ferns and fern allies, and winter botany. Think of these as a kind of lab manual. We will not go through each part of the exercise but the information is there if you need it for your project. At the end of the syllabus are some readings on mushrooms.

Peat Mosses B Species of Sphagnum

Some of the most frequently encountered wetland plants are peat mosses, species of the genus Sphagnum. Yet they are virtually never included in reports or studies as species, only as Sphagnum sp. This despite the fact that peat mosses are highly site specific and could be excellent indicators of environmental factors. For this reason it is important to know how to identify local species. Unfortunately, we do not (yet) have a suitable, simple key for our species. However, there are only about a dozen species in the Tidewater area and with a little effort it is possible to recognize these in the field.

We will devote part of an "indoor" lab to the examination of the microscopic features of peat mosses. Because peat mosses can be collected and preserved any time of the year, we can examine them in the field first, collect material, and do the microscopic study at any time. If available, examine living specimens of a peat moss. Place a plant under the binocular microscope. Locate the following structures: capitulum, stem, fascicle, spreading branches, pendant branches, leaves, stem leaves. Reproductive structures may be present but these are not usually essential to species determination. These features characterize the genus. It is not difficult to determine the genus even in the field. Species determination is another matter! At least initially, you will have to depend upon microscopic structures to determine species. For this work you will need the following equipment/supplies:

Binocular microscope

Compound microscope

Slides and cover glasses (inexpensive plastic coverslips are fine)

Forceps with fine point

Teasing needle

Watch glasses

Soup or tablespoon!

Bunsen burner

Water

Methylene blue stain

Crystal violet stain

Razor blades (double edge razor blades are best and also inexpensive)

After reviewing the structure and morphology of peat mosses in your book (pages 22-25), review these features using Sphagnum perichaetiale Sphagnum perichaetiale Images which is in the section Sphagnum.

Obtain a few plants. Locate the capitulum. Remove a capitulum with a few fascicles and place it in a spoon with enough water to cover it and boil. Locate the fascicles, remove a few branches from the fascicle. Using the binoc, place the branch on a slide and remove leaves. I do this by holding the branch with the forceps and scraping off the leaves with a teasing needle. Place a drop of water (without stain) on the slide and cover with a coverslip. Examine with low power and locate the branch. The branch consists of a central parenchyma region surrounded by "sclerenchyma" tissue. The outer layer of the branch is called the cortex and is one cell layer thick. (In contrast, the cortex of the stem is several cell layers thick.) Note the conspicuous spiral markings in the walls of the cortical cells. This feature places this species in the section Sphagnum.

But for species determination more work is needed! Again, take one of the capitula that has been boiled and place it on a microscope slide under your binoc. Using a razor blade slice off the thinnest possible sections by cutting across the capitulum. Save the sections, remove the capitulum and mount the sections in a drop of water with a coverslip. Examine under low power with the compound microscope. Locate sections that are cross sections of the leaves; these will appear "V" shaped. Switch to high/dry (45X) and locate the green cells. Remember that the leaf of Sphagnum is one cell thick. The larger cells are non-living at maturity and termed hyaline cells. One of the features used to distinguish among species is the relationship of the green cells to the hyaline cells. For example, in S. perichaetiale the green cells are narrow, with thickened end walls that extend to both surfaces of the leaf. In other species, the green cells may be entirely included or exposed at only one surface. Some green cells are trapezoidal in shape. It is important to learn how to distinguish these cells as they are an important diagnostic feature of peat mosses.

In some peat mosses, the wall of the green cell is ornamented by fibrils or papillose outgrowths. Examine pictures and images of these. For example, S. papillosum. Images

The next steps involve staining. I prefer methylene blue but both this stain and crystal violet are available. Take a few branches that have been boiled and place them in a watch glass with a drop of stain. Rinse off the stain. Place the branch on a slide under the binoc and remove branch leaves. While doing this, locate the stem leaves. These are leaves attached to the branch and not in fascicles. Usually, stem leaves are different in shape and structure than the branch leaves. Remove all but a few leaves of a branch. Mount the branch axis and leaves in a drop of water with a cover slip and examine under low power. Notice the general shape of the cells. In this section of the genus, leaves are described as being cucullate or hooded. Carefully distinguish between leaves that are curved on both sides but are not cucullate. Cucullate leaves must be hooded, that is, there is a distinct, curved hood at the end of the leaf. Find the tip of the leaf with the minute teeth.

The stain will help you to see clearly the arrangement of the cells in the leaves. Notice that most of the leaf is composed of hyaline cells. The green cells are sandwiched between hyaline cells. Hyaline cells may have distinct ornamentation in the form of spirals. Locate the pores. In S. perichaetiale these are located at the corner of the cells.

Now, examine the axis of the branch. Note the cortical cells. You will once again see the spirals characteristic of the cortical cells in species of this section. Locate the pores in the branch cortical cells.

Next, take a stained stem and place it under the binoc. Locate a few stem leaves. Compare their shape and structure to that of the branch leaves. Pay particular attention to the tip of the leaf and to the type of cells that are found on the margin of the leaf.

Peat Mosses of the Tidewater, Virginia area

Sphagnum

Species in this section have cortical cells of the stem with spiral thickening. These are seen by making hand sections of the stems and mounting in water or stain.

Sphagnum magellanicum. Sphagnum magellanicum Images This is the characteristic peat moss of hummocks in northern bogs. I have not seen it in our area but it has been collected in bogs and at the margins of swamps.

Sphagnum perichaetiale. Sphagnum perichaetiale images Common in our area in burned areas (such as the Blackwater Ecologic Preserve) and in ditches. Often, the stem is very dark.

Sphagnum papillosum image. This is an attractive species which reaches its southern limit in North Carolina, being much more common further north. As noted above, the walls of the green cells are usually papillose.

Sphagnum palustre. Sphagnum palustre imagesAlso a very common peat moss.

Sphagnum henryense. Sphagnum henryense Images This and the above species are easily confused. They are separated, in part, on the character of the green cells of the branch leaves. This moss is named after Cape Henry and is frequent in our area.

Sphagnum affine. Found at Blackwater Ecologic Preserve. This species often forms extensive mats rather than mounds or hummocks.

Section Rigida

In our area, represented by only the following species. This has very small leaves, hence the specific epithet. Compare the size of the stem and branch leaves.

Sphagnum compactum. Sphagnum compactum Images This species prefers habitats drier than our other peat mosses.

Section Cuspidata

Plants in this section are usually found in wet depressions and are occasionally aquatic.

Sphagnum cuspidatum. Sphagnum cuspidatum Images One of the most common aquatic peat mosses in our area (and throughout much of Eastern North America). Abundant, for example, in the ditches in the Dismal Swamp during the winter. When dry, it resembles "wet kitten fur", a very apt description. It can be confused with the following, which is much less frequent.

Sphagnum torreyanum. Sphagnum torreyanum Images This is a handsome moss. Note the relatively large buds and distinctive green color. Examine the cortical cells of the branch to find the retort-like pores. Large populations are found at the Zuni Pine Barrens Preserve. This is our largest peat moss.

Sphagnum recurvum. Less frequent than the above, but also known from the preserve.

Section Subsecunda

Leaves in this section are often sub-secund, that is, all turned to one side.

Sphagnum lescurii. Sphagnum lescurii Images This is a widespread species. I have seen it in swamps throughout the Southeast. It usually forms small mounds. The branches of the capitulum typically bend down.

Section Isocladus

Crum calls this group of mosses "Distinctive in the extreme..." There is only one species, Sphagnum macrophyllum which I have only seen in the Dismal Swamp. It is an aquatic moss with very large leaves. image

Section Acutifolia

The three representatives of this section have been collected at the Blackwater Ecologic Preserve. I find species in this section to be the most difficult to identify.

Sphagnum capillifolium. Sphagnum capillifolium Images Often with a red capitulum, this moss is common at the preserve. Recent research strongly suggests that S. tenerum should be recognized as a distinct species rather than as a subspecies of S. capillifolium.

Sphagnum molle.

Sphagnum bartlettianum.

With just a little experience, it is possible to determine species in the field and to see the very specific niches they occupy. This is best done on a field trip so we shall examine as many different populations at the Blackwater Ecologic Preserve as possible.

We are fortunate to have the collections made by Gisela Grimm who devoted the latter years of her life to studying the local bryoflora. Her specimens are in the ODU herbarium. Their value is enhanced by the fact that they have been examined and annotated by Lewis Anderson of Duke University.

Ferns and Fern Allies of Tidewater Virginia

This is intended as guide to the ferns and fern allies of the Tidewater area. I have followed Flora of North America (FNA) for nomenclature. FNA is available on-line at FNA

Ferns and fern allies may be homosporous, producing one type of spore or heterosporous, producing two types of spores that are morphologically distinct. Megaspores are larger and produce the female gametophyte. Microspores are much smaller and produce the male gametophyte.

The term "fern allies" is a sort of "catch all" for plants that have a fern like life cycle but are not true ferns. Put another way, they produce spores from which gametophytes and gametes arise. Botanists consider these to be the most primitive of all vascular plants. In previous geological epochs, they were the dominant land vegetation.

Psilotum nudum Whisk fern. Psilotum nudum Images Not known from Virginia but reported from Chowan County, North Carolina, from a hardwood swamp with an immense population of Dryopteris ludoviciana. Should be looked for in the Tidewater area. See Perry, J. P., III and L. J. Musselman. 1994. Psilotum nudum new to North Carolina. American Fern Journal 84 (3): 12-14.

The generic names of many of the club mosses have been revised, based on recent studies. See FNA for notes and comments. Lycopodium and segegrate genera Images

Lycopodiella appressa Appressed bog club moss. This is distinguished from the following species by having a strobilus not much wider than the upright shoot. In this genus, there are horizontal stems that creep along the ground. From these arise the leafy upright stems.

Lycopodiella alopecuroides Foxtail bog club-moss. Found on moist sand in open areas in the Coastal Plain.

Pseudolycopodiella caroliniana Some populations of this still exist in Sussex County.

Selaginella apoda Meadow spike-moss. Resembling a moss, this diminutive plant is found in a variety of moist habitats but is often overlooked. Heterosporous.

This family consists of the single genus Isoetes. We are studying the southern species and have all growing in containers in the herbarium. Examine fresh material. Quillworts, as species of Isoetes are known, are one of the least studied groups of fern allies and perhaps one of the least studied of all vascular plants in the southern United States. They are all listed as obligate aquatic plants but few are actually true aquatics. Rather, they are adapted for habitats that are inundated and then dry out. Quillworts are probably much more common than generally realized. They are heterosporous. In general, mature megaspores are necessary to determine species. You will be provided with handouts that illustrate spore features. The following species are common in our area. Isoetes engelmannii Engelmann's quillwort. Check out the ODU Isoetes site at: ODU Isoetes site

Isoetes saccharata These two quillworts are virtually indistinguishable in the field and often grow together! They may be found in any freshwater habitat. Isoetes saccharata may be a complex of several species. It is the characteristic quillwort of freshwater tidal marshes. Pertinent literature includes: Musselman, L. J. and D. A. Knepper. 1997. Chesapeake Bay Quillworts. Wetland Journal 9(1): 3-6; Musselman, L. J., R. D. Bray and D. A. Knepper. 1997. Isoetes H carltaylori ( Isoetes acadiensis X I. engelmannii ), a new interspecific quillwort hybrid from the Chesapeake Bay. Canadian Journal of Botany 75(2): 31-39; Musselman, L. J., R. D. Bray and D. A. Knepper. 1996. Isoetes H bruntonii, a new hybrid quillwort from Virginia. American Fern Journal 86(1): 8-15; Musselman, L. J., D. A. Knepper, R. D. Bray, C. A. Caplen and C. Ballou. 1995. A new Isoetes hybrid from Virginia. Castanea 6(3): 245-254; Musselman, L. J. and D. A. Knepper. 1994. Quillworts of Virginia. American Fern Journal 84(2): 48-68.

True ferns are divided into two large groups: leptosporangiate and eusporangiate . The eusporangiate ferns have sporangia that develop from both superficial and internal cells. Sporangia are large and contain large numbers of spores. Leptosporangiate ferns, on the other hand, have sporangia that develop from surface cells. Their sporangia usually contain 64 spores or a multiple of that number. There are only two families of eusporangiate ferns in our flora.

Ophioglossaceae

Botrychium simplex Least moonwort. With a wide ecological amplitude, this common fern is occasionally found in wetlands. Botrychium species Images

Ophioglossum petiolatum Stalked adder's-tongue. This tiny fern has been reported from Virginia Beach but I have not seen it any closer than Chowan County, North Carolina. It appears in mid- winter and dries by Spring. Ophioglossum petiolatum Images

Ophioglossum vulgatum Southern adder's-tongue. In early Spring this is a frequent component of the flora of damp woods and along intermittent streams. Probably more common than realized and seldom collected in our area.

Osmunda cinnamomea Cinnamon fern. Osmunda cinnamomea Images Common in a variety of moist situations in our area but generally in drier sites than the following species. Osmunda is unique among the ferns we are considering in having green spores.

Osmunda regalis Royal fern. Osmunda regalis Images A common and attractive member ofour wetland flora.

Dennstaedtiaceae

Dennstaedtia punctilobula Hay scented fern. Dennstaedtia punctilobula images Including this as a wetland species is sort of a 'reach' but it does occur at some moist sites in the Dismal Swamp and elsewhere. The circular indusium is unique in our ferns as is the odor of fresh cut hay when the frond is crushed.

Thelypteris noveboracensis New York fern. Thelypteris noveboracensis ImagesCommon in Tidewater in a variety of habitats. Often found in drier sections of swamps and along streams.

Thelypteris palustris Marsh fern. Thelypteris palustris Images Common in freshwater marshes in our area. Our plants are var. pubescens as var. palustris occurs in Eurasia. Compare the lower pinnae of this species with T. noveboracensis.

Phegopteris hexagonoptera Broad beech fern. Phegopteris hexagonoptera ImagesInfrequent in our area in moist woods and along rivers.

Woodwardia areolata Netted chain fern. Woodwardia areolata images One of our most common wetland ferns. Note the dimorphic fronds. The vegetative fronds are often confused with those of Onoclea sensibilis. An easy way to distinguish them is by examining the leaf margin. The margin of Woodwardia has minute teeth that form a "www" like margin. This is in contrast to the margin of Onoclea that is smooth, like "ooo". Some authors have placed this species in the genus Lorinseria.

Woodwardia virginica Virginia chain fern. Woodwardia virginica Images Dimorphic fronds are not found in this wetland species. In general, I associate the Virginia chain fern with wetter situations than the netted chain fern. This species may be confused with Osmunda cinnamomea but the chain-like venation on the abaxial surface is diagnostic.

Asplenium platyneuron Ebony spleenwort. Asplendium platyneuron Images Not typically a wetland species but aggressive and sometimes invading (but not persisting in) wetlands.

Onoclea sensibilis Sensitive fern. Onoclea sensibilis Images The common name refers to the susceptibility of the leaves to even a light frost even though the fern occurs as far north as central Ontario. Dimorphic, the vegetative leaves of this fern are confused with those of the netted chain fern. Common in our area in ditches and margins of streams.

Athyrium filix-femina Lady fern. Athyrium filix-femina Images Two varieties of this common fern of wetlands are found in our area. They are: A. filix-femina var. angustum with indusia not glandular and yellow spores and A. filix-femina var. asplenioides with indusia glandular (or not!) and dark brown spores.

This genus is one of the most diverse and intriguing group of vascular plants in the Dismal Swamp. Note the chromosome numbers and hybrids found in the swamp. Hybrids are characteristically intermediate between their parents. Some pertinent literature includes: Nickrent, D. L., L. J. Musselman, L. A. Pitchford and D. W. Sampson. 1978. Distribution and ecology of Dryopteris in southeastern Virginia and adjacent North Carolina. American Fern Journal 68: 45-51. Wagner, W. H., Jr. and L. J. Musselman. 1979. Log ferns of the Great Dismal Swamp. pp 127-139 in: P. W. Kirk, Jr., editor. The Great Dismal Swamp. Charlottesville: University Press of Virginia. 427 pp xiv; Wagner, F. S. and L. J. Musselman. 1982. The occurrence of the southern woodfern, Dryopteris H australis (Wherry) Small. Castanea 47: 182-19; Musselman, L. J. 1984. Dryopteris hybrids in the Great Dismal Swamp. National Geographic Society Research Reports 17: 619-624. And, the most recent treatment--Heafner, K.D. 2000. Log ferns, genus Dryopteris, of the Great Dismal Swamp. Pp. 59-65, in the Natural History of the Great Dismal Swamp (R.K. Rose, ed.). Old Dominion University Publications, Norfolk, Virginia, and Omni Press (OMNI), Madison, Wisconsin.

Sexual Taxa

Dryopteris intermedia Fancy fern. Dryopteris intermedia Images Compare the morphology of this species with the following, paying particular attention to the features of the innermost pinnules of the lower pinnae. Fancy fern is also characterized by its glandular hairs on the indusia and, when young, on the rachis. 2 n=41.

Dryopteris carthusiana Spinulose wood fern. Dryopteris carthusiana Images This is more common in the Dismal Swamp than the fancy fern but superficially resembles it. 2 n=82.

Dryopteris celsa Log fern. Dryopteris celsa Images First described from the Dismal Swamp where huge populations are still found. Like all our species in this genus, the log fern is evergreen. 2 n=82.

Dryopteris ludoviciana Southern wood fern. For many years we searched the Dismal Swamp to find this species because some of the hybrids found in the swamp had the southern wood fern asone of the parents. About ten years ago, a population of several thousand plants were found in a swamp in Chowan County, North Carolina. This northernmost population may explain the involvement of this species in Dismal Swamp hybrids. 2 n=82.

Dryopteris cristata. Dryopteris cristata Images Crested wood fern. With erect narrow fronds, this species is very rare in our area. A small population persisted in the Dismal Swamp for many years. Crested wood fern is at the southern edge of its range in our region. 2 n=164.

Hybrids

The proper way to note hybrids is by the placement of a multiplication sign before the specific epithet. This is not always possible with all word processing. Dryopteris xaustralis. The hybrid between D. celsa and D. ludoviciana. 2 n=123.

Dryopteris xseparabilis. Dryopteris separabilis Images Certainly the most beautiful of all the Dismal Swamp log ferns, this has a chromosome number of 2 n=123.

Dryopteris cristata X D. celsa. This hybrid has never been formally named and is apparently very rare. 2 n =164.

The resurrection fern, Pleopeltis polypodioides Pleopeltis polypodioides Images, also known as Polypodium polypodioides, is one of our most common epiphytes. It is usually found on trees in moister sites, such as river banks. Note the distinctive trichomes on the lower surface. These allow for rapid hydration after desiccation.

Marsileaceae

This is a most unfern-like fern! The leaves look like a four leaf clover. Reproduction is highly specialized. The sori are contained in a hard seed-like structure borne under water (in species under the soil) on the rhizome. No native species are known in Virginia. A population was discovered in the city of Chesapeake in October 2001, established along a drainage canal. Marsilea mutica. Images

Azolla caroliniana Azolla. Azolla caroliniana Images Unique among our fern flora in being a free floating plant. The fronds contain the cyanobacterium Anabena azollae. I use this fern as a source of the microorganism for class.

Athyrium filix-femina var. angustum

Athyrium filix-femina var. asplenioides

Asplenium platyneuron

Azolla caroliniana

Botrychium simplex

Dennstaedtia punctilobula

Dryopteris australis

Dryopteris carthusiana

Dryopteris celsa

Dryopteris cristata

Dryopteris cristata X D. celsa

Dryopteris intermedia

Dryopteris ludoviciana

Dryopteris separabilis

Isoetes engelmannii

Isoetes saccharata

Lycopodiella alopecuroides

Lycopodiella appressa

Marsilea mutica

Onoclea sensibilis

Ophioglossum petiolatum

Ophioglossum vulgatum

Osmunda cinnamomea

Osmunda regalis

Phegopteris hexagonoptera

Pleopeltis polypodioides

Psilotum nudum

Selaginella apoda

Thelypteris noveboracensis

Thelypteris palustris var. pubescens

Woodwardia virginica

Woodwardia areolata

OTHERS:

INTRODUCTION TO WINTER BOTANY

Winter botany is used to refer to plants, chiefly woody plants, in their dormant condition. In our flora, this occurs in the winter but in some climates the dormant season is the dry season. Plant identification principles for winter botany are the same principles used during the growing season. This means that conservative features, ie, those not strongly influenced by the environment, are the most dependable to use. The entire classification scheme of angiosperms is based more or less upon the characters of the flowers which are conservative structures. For winter botany, we use mainly characters of scars.

Two points regarding winter botany need to be emphasized. I am calling these scope and resolution . By scope I am referring to the scope number of plants within our flora which can be accurately identified in their winter condition. The scope of winter botany is much narrower than that of the growing season. In general, woody plants are easier to identify in winter condition than herbaceous plants. But with some experience you can learn to identify grasses by such things as ligules, etc. You won't find these features in any book dealing with the plants of our area! They are features which you must learn for yourself. Remember, the characters you discover may be as accurate, though less familiar, as other characters. I am using the term resolution to refer to the different level of resolution accuracy of species determination in winter botany. For example, it is always possible to determine which group (white or red and black) an oak belongs to, but in some cases it may be impossible to accurately determine the species from twigs alone.

Woody plants have a suite of characters useful for identifying them in winter condition. View the attached PDF file (put in this form to preserve formatting on the web). Characters of Woody Plants in Winter Condition

For images of terminal buds image
For images of pseudoterminal buds image
For images of superposed buds image
For images of hidden buds image
For images of naked buds image
For images of hidden buds image
For images of pith image
For images of bundle scars image
For images of bark image

Blakslee, A. F. and C. D. Jarvis. New England Trees in Winter. Storrs Agricultural Experiment Station Bulletin no. 69. 1911. (Dover Reprint, 1972) Storrs, Conn. Excellent descriptions andphotographs.

Harlow, W. M. 1942 (Dover Reprint 1957). Trees of the Eastern and Central United States and Canada.288 pp., illus. Dover Pub. Co. Contains descriptions of trees and includes pictures of bark and winter twigs. Interesting notes on uses are included.

Harlow, W. M. 1941 (Dover reprint 1959). Fruit Key and Twig Key to Trees and Shrubs. Dover Pub. Co. This is perhaps the best key for woody plants in winter condition, profusely illustrated.

Harrar, E. S. and J. G. Harrar. 1946 (Dover reprint 1967). Guide to Southern Trees.70 pp., illus. Dover Publications. Illustrations for all species are not included but winter twigs are shown for many species. Winter keys not included.

Jacques, H. E. 1946.How to Know the Trees. Wm. C. Brown Co., Dubuque, Iowa.166 pp., illus. Winter twigs are included with most illustrations.

Muenscher, W. C. 1946 (Reprinted 1963). Keys to Woody Plants.108 pp., illus. Comstock Publishing Associates, Ithaca, N. Y. This handy little volume is essentially a collection of keys to woody plants. It is especially helpful in keying plants to species.

Petrides, G. A. 1958.A Field Guide to Trees and Shrubs. Peterson Field Guide Series.431 pp., illus. Houghton Mifflin Co., Boston. A separate winter key is included in the appendix.

Preston, R. J. Jr. and V. G. Wright.1976.Identification of Southeastern Trees in Winter.113 pp., illus. North Carolina Agr. Extension service, Raleigh. An excellent guide with good introductory material and workable keys.

Rogers, W. E. 1935 (Dover reprint 1965). Tree Flowers of Forest, Park, and Street.499 pp., illus. Dover Pub. Co. This book is beautifully illustrated with photographs and exquisite line drawing of winter silhouettes of trees.

Trelease, W. 1931 (Dover reprint 1967). Winter Botany.396 pp., illus. Dover pub. Co.This classic volume has excellent keys and diagrams.

Watts, M. T. 1970.Winter Tree Finder. Nature Study Guild. Berkeley: Nature Study Guild, Box 972, Berkeley, Ca. 94701.This cleverly designed pocket sized booklet features "picture keys" to most trees in winter condition.

Mushrooms

As of August, fall 2001 looks like it will be a good mushroom year. The mushroom flora is dependent upon rainfall and temperatures. By my reckoning, this will be a good year for 'shrooms.

Begin collecting your mushrooms NOW! Mushrooms are fickle, you can not predict when they may appear. You will be instructed how to preserve mushrooms for your collections. One important aspect is the preparation of spore prints. Be certain to use white paper for your spore prints. During one of our "indoor" sessions, we will examine spores and test them with Melzer's reagent (a simple test involving a starch reaction). Spores from your spore prints will work fine for this.

This iodine test solution has the following composition: 44 parts water, 3 parts potassium iodide, 1 part iodine, 40 parts chloral hydrate. Melzer's reagent is toxic!! The reaction is immediate. Spores may be amyloid (staining black immediately) or inamyload (no reaction but bear in mind that Melzer's is brown itself in color). There is an intermediate reaction termed dextrinoid in which the spores stain brown, this is best observed by putting the spores on a slide, applying the stain, and examining under the microscrope. Within the same genus, spores can be amyloid or inamyloid for example Amanita. Amanita caesarea spores do not stain while those of A. vaginata are amyloid.

One of the best web resources for mushrooms that I have found is MycoWeb. Also good for some of the mushrooms found in our region is the Duke University site. For mushroom toxins, try this FDA site and the University of Wisconsin-La Crosse site

No doubt there are others. If you find a good site, please let me know.

I have assembled pictures of some of the more abundant genera in our area. They are listed below by genus name. Clicking on "image" will take you to a selection of images. With few exceptions, all pictures are from our region (southeast Virginia and adjoining North Carolina). However, bear in mind that mushrooms, unlike vascular plants, can have a very broad distribution for a single species. For example, Amanita muscaria is found in both Asia and North America. Note that "indet.", abbreviation for indeterminata, means that the fungus has not yet been identified to species.

BASIDIOMYCOTA

Agarics (gilled mushrooms)

Agaricus image

Agrocybe image

Amanita image

Armillariella image

Cantherellus image

Chlorophyllum image

Collybia image

Coprinus image

Cortinarius image

Craterellus image

Gymnopilus image

Laccaria image

Lactarius image

Naematoloma image

Pleurotus image

Pluteus image

Russula image

Stropharia image

Boletes (pore mushrooms)

Austroboletus image

Boletus image

Grifola image

Laetiporus image

Leccinumimage

Suillus image

Gastromycetes (puffballs and relatives)

Calvatia image

Lycoperdon image

Phallus image

Pisolithus image

Pseudocolus image

Scleroderma image

Coral fungi (and relatives)

Clavariadelphus image

Sparassis image

Jelly fungi (tree ears and relatives)

Leotia image

Tremella image

ASCOMYCOTA

Morels, False morels, Saddle Fungi

Helvella image

Morchella image

Truffles

Terfezia image

Cup Fungi

Fungi parasitic on fleshy fungi

Hypomyces image

Microscopic structures (lamellae, pores, basidia, spores, cystidia)

Asci lining Morchella image

Lamellae of the gill mushroom, Coprinus image

Pores of the pore mushroom, Boletus image

Spores image

Cystidia image

Basidia image

Cuticle image

Toxic Mushroom Determination

1. Try to locate where the mushroom was growing and collect additional mushrooms. Take care to carefully dig them, as the portion underground may be essential for accurate identification. Collect in various stages of development, if possible, to ensure that some will produce spores. Spores are necessary for determination of most mushrooms.

2. Place the mushrooms in a paper -- Must be paper!! B bag. Mushrooms will sweat and rapidly decompose in a plastic bag. Do not wash the mushroom.

3. Bring the mushroom to room 110, Mills Godwin Building on the Old Dominion University campus. Include the name and phone number of the physician and the approximate time that the mushroom was ingested.

4. The mycoflora of our area is imperfectly known, so that placing a species name on the specimen may not be possible. In my experience, however, it is likely that the patient (usually a child) has ingested one of the more frequent and therefore better known fungi.

There are various classes of toxins in mushrooms, the most deadly being phallotoxins and amatoxins which do permanent damage to the liver. These are known almost exclusively from the species in the genera Amanita and Galerina . Other mushrooms cause serious gastrointestinal upset. Some are hallucinogenic but also contain toxins. In some cases, the reaction to eating mushrooms is a simple food allergy.

In my more than twenty years of identifying toxic plants and mushrooms, none have been fatal. But deadly poisonous mushrooms are part of our native mycoflora and any case of ingestion of an unknown mushroom must be considered potentially very serious.

Lytton John Musselman

Are you guilty? Not a pretty sight1 . Decapitated bodies. Broken parts strewn carelessly. All are victims of violent, senseless abuse. I witness it on campus at the end of the summer and the beginning of the new semester, especially when it is hot and humid.

Mushroom abuse--a little known form of violence on the ODU campus.

How can we stop this? How can we show that mushrooms need to be cared for, not kicked? Do we need mushroom sensitivity training at Preview? Is this the sort of program fraternities could take on? We are fortunate at ODU to have a diversity of mushroom species. Perhaps as many as thirty occur on campus, a valuable resource for my mushroom course. And their presence adds diversity and intrigue to our campus. Apart from mushroom devotees, however, they are not only unappreciated but positively reviled.

Why? Perhaps people think mushrooms are intrinsically evil, because they seem to appear suddenly from the nether world and disappear below ground just as suddenly. Or, mushrooms may be associated with a drug subculture. Or they are feared for their toxins. Our campus mushrooms are neither psychedelic nor evil. Some are toxic, but so are some common plants which are valued. They are only doing their job of recycling organic material. In fact, their appearance is dependent on nothing less mundane than weather.

Hot, humid weather brings on the most spectacular mushroom displays on campus. Mushrooms are mainly water. Using hydrostatic pressure, mushrooms enter campus life literally pumped up only to be met with disgust and jeers-- and violence.

The largest of the late summer/early fall mushrooms is the green gilled lepiota, Chlorophyllum molybdites. Chlorophyllum molybdites images Often these mushrooms form a nearly perfect circle on the lawn called a "fairy ring," another image from the supernatural. Their growth and development are a marvel of nature. First, a drum stick shaped brownish white structure emerges from the grass. On the second day the cap expands, sometimes to a radius of 8-10 inches. Ghostly white, the cap resembles a summer parasol. It may have light brown scales on the cap. Overnight its appearance changes, especially if the weather is hot and dry. It becomes brown and the edges of the cap turn up. From a drum stick, to a parasol, to a pagoda in four days or less!

If you remove the cap at the parasol stage and place it on a sheet of white paper for a few hours, an intricate pattern of sordid green spores is deposited. These green spores give the mushroom its common name and its scientific name. Chlorophyllum means green leaf. Molybdites is from molybdenum, a trace metal that forms compounds that are green. The green gilled lepiota is toxic if ingested. Symptoms include serious gastrointestinal distress. NEVER eat an unknown mushroom! Remember the old adage: There are Old mushroom hunters and there are BOLD mushroom hunters but there are NO OLD BOLD mushroom hunters!

Edible mushrooms also grace our university campus. Right here within sight from my office in Mills Godwin are several populations of the delectable mushroom French chefs refer to as champignon , a close relative of the commercial mushroom. Not available in stores, this fungus has a distinct flavor---a combination of filet mignon and black walnut. Just last week I collected ten caps walking across campus to my house in Larchmont. Sauteed in butter, they never saw the light of another day and will never return to their nether home. A form of abuse? No, a form of use!

I wonder if abusers think the organism's life is snuffed out by a football kick. Hardly. As any student of mushrooms knows, the visible above ground part of the fungus is only a tiny part of the total organism. Almost the entire mushroom is underground, hidden from view and safe from abuse. Mushrooms are the largest of all known creatures. Bigger than blue whales, redwoods, and even dinosaurs. Scientists reported one mushroom in Upper Michigan that spanned more than a county!

Mushroom abusers take note--your flailing at these defenseless, fleshy denizens of the lawn is futile. Pick on someone your own size!

INTRODUCTION

Mushroom exposures can invoke anxiety in the lay public and even in the most experienced physicians2 . The typical exposure scenario may involve a curious child who elected to harvest and sample a mushroom found in the yard. The child eventually tells a sibling, caretaker or parent about the episode which prompts an urgent call to a poison information center or physician or results in a hurried trip to an emergency department. Both the physician and parent are reminded of the anecdote about mushroom poisoning:

A There are OLD mushroom hunters...

There are BOLD mushroom hunters...

But there are NO OLD-BOLD mushroom hunters!"

Thoughts of the child's survival immediately come to mind. The child's " stomach is pumped" and furious efforts are made to identify the mushroom from the gastric lavage returns by trying to compare the remnants to pictures of mushrooms in a mycology reference text. The parents are sent home to find samples of the mushroom that may have been eaten. The emergency department staff attempts to locate an individual who can identify the mushroom to determine if exotic antidotes must be administered.

This exercise in futility and anxiety occurs daily throughout the United States. In reality, there are poisonous mushrooms but the typical exposure involves the ingestion of an "LBM" - Little Brown Mushroom! No symptoms develop, the child is fine and life goes on. In fact, only 14 mushroom-related fatalities (out of 85,556 documented mushroom exposures) have been reported to the American Association of Poison Control Centers over the last eleven years! This represents a fatality incidence of only 0.016% compared to a 23-fold greater incidence of 0.37% following antidepressant over dosage.

Nearly 75% of mushroom exposures involve children less than six years of age. It is rare for a fatality to occur in this age group. Most fatalities involve adults who forage for delectable mushrooms and fail properly to identify the mushrooms before consuming them. Other tragic cases involve individuals who seek hallucinogenic mushrooms, but unknowingly pick a mushroom with potential to produce a profound hepatotoxicity. While there are only a limited number of very toxic mushrooms, the best advice is to purchase mushrooms from the grocery store unless the individual is adequately trained in mushroom identification

Only exposures involving highly suspect mushrooms or in symptomatic patients necessitate absolute identification of the mushroom. Locating a mycologist to identify the mushroom is often a difficult task. Poison information centers usually have consultants available to assist in mushroom identification in the rare circumstance when that is necessary. To reiterate, most mushroom exposures do not result in the development of symptoms and require no heroic intervention. However, there are several common classes of poisonous mushrooms which have general toxidromes, knowledge of which may be useful in the diagnosis and treatment of mushroom poisoning. This issue will provide an overview of the salient features associated with each class.

GENERAL APPROACH TO MUSHROOM EXPOSURE

Despite the fact that most mushroom exposures involving children have a favorable outcome, it may be advisable to induce vomiting with syrup of ipecac if the exposure is recognized within approximately one hour of the ingestion. Emesis may be induced in the home. If there is a substantial delay and no symptoms have developed, observation maybe sufficient. Activated charcoal administration is a suitable alterative in patients who have sought assistance in an emergency department. It is prudent to save a sample of the mushroom placed in a paper bag and in the refrigerator for possible future identification in the unlikely event that the patient becomes symptomatic. This is not always fail-safe since poisonous and nonpoisonous mushrooms may grow side- by-side.

As a general rule, if symptoms develop within approximately two hours of the ingestion, it is unlikely that the mushroom is one of the potentially fatal hepatotoxic varieties. There is often a delay of several hours, usually over six hours, before symptoms develop if a very poisonous mushroom has been ingested. Once again, caution must be exercised since an individual may ingest poisonous mushrooms which produce early but not life-threatening symptoms, in conjunction with hepatotoxic mushrooms which produce a delayed onset of symptoms-the delayed symptoms falsely may be assumed to be associated with the less toxic variety. These problems reinforce the need to seek mushroom identification in patients who become symptomatic. Some symptoms associated with mushroom poisoning are identical to those observed with food poisoning. Be aware that food poisoning may be the etiology of the illness. A careful history of the patient's illness and information about others who may have eaten the same meal and possible mushroom identification may resolve this dilemma. All individuals who become symptomatic following the ingestion of a possibly poisonous mushroom should be referred to the emergency department for evaluation. Good supportive care, symptomatic treatment and fluid and electrolyte replacement are adequate therapy in most mushroom poisoning cases.

COMMON CLASSIFICATIONS OF MUSHROOM POISONING

Cyclopeptide Poisoning

No group of mushrooms instills more fear or is more toxic than those containing cyclopeptide amatoxins. The synonyms for the mushrooms which contain these are indicative of their morbid potential-"Death Angel, @ "Destroying Angel, @ "Death Cap. @ The Amanita species [sic] is responsible for most of the cyclopeptide-related fatalities and small amounts can be profoundly toxic. Members of the Galerina species [sic] are generally smaller mushrooms and contain less amatoxin per gram of mushroom. While they are very toxic and have the potential to produce death, they are less often associated with fatal outcomes.

These mushrooms contain numerous cyclopeptides, but amatoxins appear to be the predominant toxins responsible for the hepatic and renal destruction which may accompany the ingestion of the mushrooms. Hepatic necrosis, similar to that produced by acetaminophen over dosage, is the primary toxic manifestation. In general there is a delay of 6-12 hours (it may be longer) before the onset of severe gastrointestinal toxicity. The delay is pathognomonic of exposure to amatoxins. Therefore, if a patient has a late presentation of symptoms following mushroom ingestion, cyclopeptide poisoning should be considered in the differential diagnosis. The initial symptomatic period may be followed by a period of subjective improvement for 1-2 days. Thereafter, the manifestations of liver and kidney failure become apparent.

The management of Amanita or Galerina mushroom poisoning is often fraught with confusion and indecision. Since the onset of symptoms is delayed, gastric decontamination is of little value unless subsequent servings of the mushrooms have been ingested. Activated charcoal may be used if the gastrointestinal symptoms, such as vomiting, do not prevent administration. There is no approved antidote available in the United States. Thioctic acid was touted to be lifesaving after early reports from Europe in the 1960s. However, clinical studies have not confirmed the efficacy of thioctic acid. Penicillin G in huge doses of up to 1,000,000 Units/kg/day has been demonstrated to be effective in animals by preventing the uptake of amatoxins by the liver. The data are encouraging but there is insufficient human experience to confirm its benefit absolutely. Cimetidine, as a P450 system inhibitor, has been studied in mice on the rationale that the amatoxins require metabolic conversion to produce the toxic metabolite. Positive outcomes ensued, but there is no human data to demonstrate efficacy. The most promising agent is silibinin, an extract from the milk thistle plant. It is not available in the United States, but European experience in toxic patients is good. Silibinin allegedly prevents amatoxins from penetrating hepatocytes.

The best therapy is good supportive care and symptomatic treatment. Penicillin and cimetidine use may be justified given the lack of other options. Hemodialysis is ineffective in eliminating the toxins but is used to treat the sequelae of the liver and renal damage. Orthotopic liver transplantation may be the only option in severe cases.

Monomethylhydrazine Poisoning

The Morel mushroom is one of the most highly-sought edible mushrooms. It is conical in shape and porous, resembling a sponge. The novice mushroom picker may pick the "false morel" which is hollow like the morel but convoluted and not porous. These mushrooms are represented by the genus Gyromitra and contain gyromitrin which is bioconverted to monomethylhydrazine (MMH), which is also a component of rocket fuel.

Like the cyclopeptide-containing mushrooms, those which contain MMH do not produce symptoms for several hours (6-12 hours), and these poisonings are often mis diagnosed as Amanita or Galerina poisonings. However, the mushrooms are so different in physical appearance that the identification can usually be made from the history alone. The initial symptoms include profound gastroenteritis and flu-like symptoms which may continue for days. Central nervous system effects of vertigo, in coordination and seizures may occur. Hepatotoxicity and hepatorenal syndrome may develop in severe cases.

The delay in the onset of symptoms and the extreme nature of the gastrointestinal manifestations often preclude the use of any type of gastrointestinal decontamination. Supportive and symptomatic care with emphasis on fluid and electrolyte replacement will suffice inmost cases. Pyridoxine in doses similar to those used to treat iso-niazid toxicity (5-20 gm) is sometimes used to treat the central nervous system toxicity since gyromitrin is a pyridoxine antagonist which ultimately influences GABA formation.

Coprine Poisoning

The "Inky Cap, @ named as such for the black fluid which elutes from the cap of the mushroom when it matures, is a common yard mushroom which often grows in "fairy rings" or circles which outline where tree stumps are decaying below the soil surface. Some mushroom hunters consume these members of the Coprinus species [sic] but they must avoid the consumption of ethanol for several days since this mushroom, in conjunction with ethanol, is infamous for producing a disulfiram-like reaction.

The reaction may include a headache, flushing, vomiting, palpitations, paresthesias, chest pain and other clinical findings consistent with a disulfiram reaction. Onset of symptoms may occur within minutes to 2-3 hours of ingestion ethanol and the symptoms may persist for 1-2 days in extreme cases. An index of suspicion and a good history can solve the diagnostic predicament which is often diagnosed as food poisoning, an allergic reaction, or Chinese Restaurant Syndrome.

Supportive and symptomatic care are the cornerstones of therapy.

Muscarine Poisoning

An age-old treatment recommendation for mushroom poisoning was the prophylactic administration of atropine. This was based upon the cholinergic symptoms which developed after ingesting some mushrooms. This recommendation was inappropriately extended to the treatment of all mushroom poisoning cases. The Inocybe and Clitocybe species have very high concentrations of muscarine which results in cholinergic poisoning-salivation, lacrimation, urination, defecation, miosis, bardycardia, diaphoresis, etc.

The presentation of symptoms, which includes nausea, vomiting and abdominal pain, is within minutes to two hours after the ingestion. The rapid onset of symptoms essentially rules out the cyclopeptide and MMH groups of mushrooms from serious diagnostic consideration

Gastrointestinal decontamination using emesis or activated charcoal may be useful if the symptoms do not prevent the administration of either ipecac or charcoal. Fluid and electrolyte needs should be monitored closely. Atropine administration may be necessary if warranted by the cholinergic symptoms.

Ibotenic Acid and Muscimol-Containing Mushrooms

The colorful Amanita muscaria, image with the orange to red cap speckled with white flecks (often referred to as warts) which are remnants of the protective veil covering the mushroom as it protrudes through soil, frequently adorns the covers of mycology books and is often portrayed in many fairy tales, including "Alice in Wonderland." Many hear only "Amanita" and conclude that death is imminent, when in actuality there are few bad outcomes following the ingestion of this mushroom.

Psychoactive compounds, ibotenic acid and muscimol, produce distortions of reality. The symptoms may be manifest within 30 minutes(once again separating this variety [sic] of Amanita from those containing cyclopeptide), persist for hours, and produce a state of inebriation (in coordination, euphoria, confusion, drowsiness). Fever and seizures can occur as manifestations of severe intoxication.

The name of the most common representative of this type of mushroom, Amanita muscaria , provides the misconception that the mushroom contains muscarine and should accordingly be treated with atropine. Muscarine is not present in pharmacologically relevant amounts and atropine should not be used. As with many other mushrooms, treatment is largely supportive and symptomatic.

Hallucinogenic Mushrooms

"Funny mushrooms, @ as they often are called due to their psychoactive properties, primarily include members of the Psilocybe and Paneolus species [sic]. For abuse purposes, the mushrooms are eaten fresh or dried, generally in large quantities to produce hallucinogenic effects.

Depending upon the presence of other food in the stomach, the quantity of mushrooms ingested and the concentration of the hallucinogens such as psilocybin, the toxic and hallucinogenic manifestations begin over a period of 30 minutes to three hours (the symptoms should rule out cyclopeptide ingestion). Inappropriate behavior, confusion, disorientation, visual hallucinations, dilated pupils and blurred vision may occur. Gastrointestinal irritation including nausea and vomiting also are relatively common. There have been reports of fever, coma and seizure activity following the abuse of these mushrooms

Most patients report to the emergency department several hours after exposure for treatment of the dysphoric aspects of toxicity and gastrointestinal component. The symptoms usually resolve within a period of six hours and supportive care is the cornerstone of treatment.

Mushrooms may not be a nutritional powerhouse like broccoli or carrots, but they are not just a tasty decoration3 . A 3.5-ounce portion (about 1.5 cups) of raw Agaricus bisporus, the common cultivated mushroom sold in supermarkets, supplies 25% of an adult's niacin needs (plus other B vitamins), more than 10% of the iron needs, more potassium than an orange, and some fiber and protein, yet only 25 calories and no fat or sodium. (Canned mushrooms are less nutritious and are loaded with sodium and, sometimes, butter.)

Many markets now also stock exotic varieties, such as orange- colored chanterelles, delicate enoki, and intensely flavorful shiitake mushrooms have slightly more calories but fewer minerals than the ordinary variety. Dried shiitake mushrooms have highly concentrated calories and minerals by weight, but because of their strong flavor they are used in much smaller quantities. Dried mushrooms must be soaked before cooking.

When buying button mushrooms, pick those with firm, plump, tightly closed caps for best texture and flavor. Avoid those that are shriveled or bruised. If the gills show, they should be pink or tan, not dark and spongy. Store loose mushrooms unwashed in a paper bag in the refrigerator-a sealed plastic bag will hasten deterioration-and use as soon as possible. Store packaged mushrooms unopened. Dried mushrooms will keep for up to six months in a cool, dark place.

The stems of fresh mushrooms are just as good to eat as the caps; trim the stems only if they're woody. Before cooking them, wash the mushrooms quickly; don't soak them. They don't need to be cooked in oil or butter; instead saute them in a little chicken broth, or broil them. Don't throw out the flavorful and nutritious liquid they yield when cooked-use it for cooking grains or vegetables. There's no need for fatty toppings, which will overpower their delicate taste.

Raw mushrooms contain potentially toxic substances called hydrazines, some of which have been shown, in large doses, to cause cancer in laboratory animals. Many hydrazines, including the most harmful types, are highly volatile and are destroyed by heat. Drying has a similar effect.

Most people don't eat large quantities of raw mushrooms. In any case, the amount of hydrazines contained in a serving of raw mushrooms is apparently small. Practically all plant foods contain natural substances that protect the plants against predators. Some of these have been shown to have adverse effects on animals, but few effects on humans. Hydrazines appear to be among this group. Still, if you eat mushrooms often, eat them cooked, not raw. There's another reason to cook your mushrooms: cooking actually makes some of the nutrients more available to the body by breaking down the fibrous cell walls and destroying some nutrient-blocking compounds.

1 From: Old Dominion University Courier 28(4): 4. 1998.

2 Reprinted by permission from: Krenzelok, E. P. 1994. Mushroom poisoning. Is there really high morbidity and mortality? Clinical Toxicology Forum 6(4): 1,2,5. I have added footnotes and items in brackets

3 University of California Berkeley Wellness Letter, May 1995