It’s that time of year again and the fungi are out and about.
So grab your camera, get a field guide and go for a fungal foray!
A brief fungal introduction
Firstly, fungi are not plants, they do not have chlorophyll. To gain energy, fungi absorb nutrients by colonising substrates (like wood or leaf litter) with filaments called hyphae, which form web-like masses called mycelium. This mostly occurs out of human sight. Those things we get so excited about, ‘Mushrooms’ are the fruiting bodies of these mycelium masses. These fruiting bodies act as agents of fungal spore dispersal, by elevating fungal spores above ground level to be carried away by wind, water and other such forces.
Commonly fungi are classified into three broad groups based on where they produce their spores. This spore placement refers to a microscopic character, though generally speaking, it is somewhat easy to visually identify which group they might belong too based on their fruiting structure.
The Basidiomycota usually produce four spores on club-shaped cells called basidia. These microscopic basidium are arranged on the macroscopic fruiting body on gills or pores, which generally are located under the ‘mushroom’ cap.
The Ascomycota usually produce eight spores in microscopic sac-like cells called asci. Fungi in the Ascomycota don’t usually look like typical ‘mushrooms’, instead they sometimes form fruiting bodies known as the ‘cup fungi form’, although they can also be ‘club shaped’.
The third major group is the Myxomycota, which is a group that includes slime moulds who are not considered true fungi (they belong in The Protoctista). Organisms in this group have characteristics somewhere between amoebas and true fungi. Apparently these funny organisms produce spores, which turn into creeping slimy masses called plasmodium, which slime around and feed on decaying organic matter and true fungi.
The above descriptions are based on my second year fungi subject and an excellent field guide by Bruce Fruher called ‘A field guide to Australian fungi’. I have used lots of words such as ‘generally’, ‘sometimes’ and ‘usually’, this is because fungi fruiting bodies have amazingly diverse morphologies, which is one of the most exciting reasons to get out into the field and take a look at some of these funky thangs.
Below is a vaguely informative drawing I found my in my second year Botany notebook. It (not so) artistically demonstrates that fungi come in all sorts of shapes and sizes and are found in a wide range of habitats; from ‘smutty’ agricultural pests, airborne yeasts, as symbionts with algae forming lichens, under the ground as Phytophthera sp. and as mushroom forming Amanita sp.
Some definitions from Raven et al (2005):
Chlorophyll: The green pigment of plant cells, which is the receptor of light energy during photosynthesis. Also found in algae and photosynthetic bacteria.
Hyphae: A singular tubular filament of a fungus, oomycete or chytrid.
Mycelium: The mass of hyphae forming the body of a fungus, oomycete or chytrid.
Basidia/Basidium: A specialized reproductive cell of the Basidiomycota, often club shaped, in which nuclear fusion and meiosis occur.
Asci: A specialized cell, characteristic of the ascomycetes, in which two haploid nuclei fuse to produce a zygote that immediately divides by meiosis; at maturity an ascus contains ascospores.
Plasmodium: Stage in the lifecycle of myxomycetes (plasmodial slime moulds); a multinucleate mass of protoplasm surrounded by a membrane.
Fuhrer, B. (2005) A field guide to Australian Fungi. Melbourne, Australia: Bloomings Books.
Raven, P.H., Evert, R.F. & Eichhorn, S.E. (2005) Biology of Plants, 7ed. New York, USA: W.H. Freeman and Company
Check out my flickr page for more images of awesome fungi: http://www.flickr.com/photos/cracoo/sets/72157624788015662/with/5874976366/