Tulasnella

This slightly waxy fruit body appeared on the underside of a fallen, long-dead eucalypt branch in a suburban garden. It is a very striking example of Tulasnella in that the fruit body is highly obvious to the naked eye and (as you see in Photo 3) keeps its colour well after being dried in preparation for becoming a herbarium specimen. In Photo 4 I show drawings of some microscopic details. At (1) there are several immature basidia, each broadening from a narrow base and (except for the leftmost, very immature) surmounted by four bulbous protrusions (the immature sterigmata). The sterigmata extend, become swollen centrally but narrow towards their apices and at each apex one spore is produced while the basidium may shrivel and you see all this at (2). These features make the genus Tulasnella easy to recognize under the microscope. The spores of this species (shown at 3) are a little curved, somewhat sausage-like, and technically they are called allantoid spores, a word derived from the Greek 'allas' - meaning sausage! The spores may exhibit a process called 'germination by repetition', shown at (4). Here, a short prong grows out from a spore and produces a secondary spore. In effect the original spore is now functioning as a basidium from which a single sterigma is produced. Germination by repetition occurs in a only a small number of genera.