Part 2 of 3
In this second installation discussing the kingdom of the fungi, let’s turn our focus to the Basidiomycetes which contains many of the most conspicuous of fungi. In fact the largest organism on Earth is not the Blue Whale or the redwood tree. It is the Armarillia (honey mushroom) in Michigan which is 1,500 years old, with an estimated weight of over 22,000 pounds. Another Basidiomycete was found to be the oldest organism on Earth. It is an underground root parasite in Oregon’s Blue Mountains which is at least 2,400 years old and extends below 2,200 acres of conifer forest.
The phylum Basidiomycota includes organisms such as mushrooms, puffballs and shelf fungi. Other members are stinkhorns, jelly fungi, boletes, chanterelles, earth stars, smuts, bunts, rusts, Cryptococcus (the human pathogenic yeast), and also Agaricus bisporus (the common mushroom served on a pizza pie). Basidiomycetes are most commonly found outdoors but can begin growing indoors under extreme conditions.
Last month we discussed that many Ascomycetes produce distinctive sac (or ascus) from which they derive their name. Basidiomycetes are filamentous fungi; many of which form a basidiocarp (or mushroom). Basidiomycetes also differ from the Ascomycetes in that many sexually reproduce using club-shaped meiospores. In April, we discovered that a group of Ascomycetes (called the mitospores) asexually reproduce using mitosis as their mechanism. Most Basidiomycetes utilize meiosis as their primary means (asexual reproduction is very rare for them).
Some common Basidiomycetes that you may see on direct examination lab reports are pictured below.
Basidiomycetes can travel by means of wind, water, or by transfer via a third party. They are often found airborne. Although the presence of Basidiomycetes in usually no means for alarm in an air sample, be mindful that these spores, too, may cause allergic reactions in some individuals.