Papers & Projects

Myxomycetes of Cedar Bog (Slime Molds)
By Karl Leo Braun

Alfred Dachnowski (1912) stated the following concerning Cedar Bog, "... notes and records made have revealed a considerable number of species hitherto supposed to be confined to states north of Ohio." It is possible that a similar situation exists concerning the "true slime molds" (Myxomycetes) of this area, but very little is known about the regionality of the slime molds, so the above can only be determined by more extensive field work. There is, however, considerable evidence that some species are limited in their distribution to specific geographical locations , perhaps the result of some curious ecological relationship. Some species are found predominantly in the temperate zones, while others seem to occur more commonly in the tropics. To my knowledge, no one has suggested that certain species are found only in bog areas, but this certainly could be the case. Although some species of Myxomycetes seem to show a preference for coniferous wood and others a preference for broad-leaved trees, most are believed to be independent of the substratum on which they grow. The author has found two species in Cedar Bog (Diachea leucopodia and Physarum diderma) growing in great abundance on the stems and leaves of the common nettle (Urtica dioica). This could be biologically significant, or pure coincidence (Braun, 1974).

The author has been collecting the true slime molds (Myxomycetes) in Cedar Bog during the summer months for over forty years. Most collections have been made in the swamp forest community, but some have been collected from the white cedar community as well. Those collected in the swamp forest have been found primarily on ground sites such as decaying logs and leaf litter. Corticolous Myxomycetes, those found growing on the bark of living trees and vines, have been found by placing the bark of the white cedars (Thuja occidentalis) in moist chambers and carefully watching for their development. The moist chamber technique (Gilbert and Martin, 1933) has been used extensively by the author to study the corticolous myxomycetes found in the white cedar community. The moist chamber technique involves collecting samples of tree bark and placing them in Petri dishes containing water soaked filter paper. The dishes are kept moist, and in a matter of days plasmodia and fruiting bodies develop which can then be studied and identified in the laboratory.

A study of the life cycle of a myxomycete (slime-mold) may well begin with the plasmodium, which is the "slime" stage that is frequently found on rotting logs and mulch piles. This is the stage in the life cycle where food is ingested. Myxomycetes are considered to be holozoic, feeding on bacteria and other organic material associated with the substratum on which they are growing. The plasmodium "creeps" around the substratum and eventually, under poorly defined conditions, clumps up to form one of several types of fruiting bodies. Spores are produced in the fruiting bodies and when dispersed will ultimately give rise to new plasmodia. The plasmodium may be carefully dried (sclerotized) and stored for later use in the laboratory. Since the life cycle can be completed in a matter of days, the "slime mold" is an excellent organism for study in the high school or college biology laboratory.

There are about 600 species of Myxomycetes known world-wide and about 215 of those have been collected in Ohio. Fifty-five species have been found in Cedar Bog, forty-seven from ground sites and eight from the bark of living white cedar tree (Keller, et al., 1989). In the United States biologists usually classify the Myxomycetes (slime-molds) as plants closely allied with the fungi. In England they are classified as Mycetozoa (fungus-animals) related to the protozoa. Some biologists believe them to be neither plant nor animal, but a very primitive group with characteristics of both called the Protista. The taxonomic treatment used here is in accord with that used by G.W.Martin and C.J. Alexopoulos (1969).

More information on the Myxomycetes, including a life cycle diagram, may be found by accessing physarumplus on a search engine such as Yahoo.

A book entitled Myxomycetes of Ohio: Their Systematics, Biology, and Use in Teaching by Harold W. Keller and Karl L. Braun has been published by the Ohio Biological Survey. To Order Address all inquiries concerning publications to:
Director, Ohio Biological Survey
P.O. Box 21370
Columbus, OH 43221-0370
Phone: 614-899-7417
FAX: 614-688-7610
EMAIL: ohiobiosurvinc@aol.com

SHIPPING AND HANDLING ***(minimum = $ 2.50 USA)***
United States 10 % $ 2.50
Canada, Mexico, and Central America 12 % $ 4.00
Europe and South America 15 % $ 6.00 †
Africa, Asia, and the South Pacific 16 % $ 7.50 †
† Surface Mail rate, email us for Air Mail or other rates.
Ohio residents add 6.75 % sales tax. To avoid confusion, please include first author and year of publication with your order if you do not use the order form provided. Orders will be sent by 4th class mail. Payment must be by MasterCard, Visa, check or money order (in U.S. dollars or drawn on a U.S. bank), or valid purchase order payable to: Ohio Biological Survey, Inc.

More information on publications dealing with the flora and fauna of Cedar Bog may be found on the OBS website.

The following is a list of all Myxomycetes so far collected in Cedar Bog: (* denotes a picture on photo page.)

Arcyria cinerea (Bull.) Pers.*
     A. denudata (L.) Wettst.*
     A. magna Rex.*
Badhamia follicola A. Lister
Ceratiomyxa fruticulosa (Muell.) Macbr.*
Clastoderma debaryanum Blytt.
Comatricha typhoides (Bull.) Rost.
Craterium minutum (Leers) Fries *
Cribraria tenella Schrad.*
    C. intricata Schrad.
Diachea leucopodia (Bull.) Rost. *
Dictydiaethalium plumbeum (Schum.) Rost. *
Dictydium cancellatum (Batsch) Macbr.
Diderma hemisphaericum (Bull.) Hornem.*
    D. chondrioderma (de Bary &Rost.) G. Lister
    D. crustaceum Peck
Didymium iridis (Ditmar) Fries
    D. crustaceum Fries
Fuligo septica (L.) Wiggers *
Hemitrichia serpula (Scop.) Rost.*
    H. stipitata (Massee) Macbr.
    H. clavata (Pers.) Rost.*
Lamproderma arcyrionema Rost.
    L. arcyrioides (Sommerf.) Rost.
Lycogala epidendrum (L.) Fries *
    L. exiguum Morgan
Metatrichia vesparium (Batsch) Nann.-Brem. *
Mucilago crustacea Wiggers *
Perichaena chrysosperma (Currey) A. Lister *
    P. corticalis (Batsch) Rost.
Physarella oblonga (Berk & Curt.) Morgan *
Physarum nutans Pers.*
    P. diderma Rost.
    P. pulcherripes Peck *
    P. viride (Bull.) Pers.
    P. citrinum Schum.
    P. globuliferum (Bull.) Pers.
    P. flavicomum Berk.
    P. cinereum (Batsch) Pers.
Reticularia splendens Morgan
Stemonitis axifera (Bull.) Macbr.*
    S. smithii Macbr.
    S. flavogenita Jahn
Trichea favoginea (Batsch) Pers.*
    T. scabra Rost.
Tubifera microsperma (Berk & Curt.) Martin *
    T. ferruginosa (Batsch) J.F. Gmel.

Corticolous Myxomycetes: Arcyria pausiaca Keller & Buben-Zurey
Calomyxa metallica (Berk.) Nieuwl.
Clastoderma debaryanum Blytt var. emperatorium Emoto
Cribraria confusa Nann.-Brem.& Y. Yamam.
    C. minutissima Schw.
Echinostelium minutum de Bary
Enerthenema papillatum (Pers.) Rost.
Licea kleistobolus Martin

Literature Cited

Braun, K.L. 1974. Myxomycetes of Cedar Bog. King C.C. and C.M. Frederick (eds.) Cedar Bog Symposium . Ohio Biological Surv. Inf. Cir. 4, 40-43. Dachnowski, A. 1912. Peat Deposits. Ohio Geological Survey Bulletin. No. 16. Forth Series. Columbus, Ohio. 424 pp.

Gilbert, H.C. and Martin, G.W. 1933. Myxomycetes found on the bark of living trees. Iowa Stud. Nat. Hist. 15: 3-8.

Keller, H.W., K.L. Braun, and M.J. Buben-Zurey. 1989. Corticolous Myxomycetes from Cedar Bog: New Records. Cedar Bog Symposium II. Ohio Historical Society. Columbus, Ohio. 38- 39.

Martin, G.W. and C.J. Alexopoulos. 1969. The Myxomycetes. Univ. of Iowa Press. Iowa. 560 pp.

Included here are black and white photos of Myxomycetes collected in Cedar Bog.

Web Sites

Here are a couple websites dealing with Myxomycetes (Slime Molds):

MyoxoWeb-a virtual field guide to myxomycetes

The Georgia Museum of Natural History and the Julian H. Miller Mycological Herbarium photo gallery