Spore ornamentation

Spores within an individual species are fairly constant in their shape and structure. However, many mushroom species differ remarkably in their spore types. Some are smooth and lemon shaped (in the genus Copelandia, for instance) many are ellipsoid (as in the genus Psilocybe), while others are highly ornamented and irregularly shaped (such as (hose in Lactariusor Entoloma). A feature common to the spores of many mushrooms, particularly the psilocybian species, is the formation of an apical germ pore. 

Microscopic Characteristics Conidiophores poorly developed, relatively undifferentiated, irregularly branched, vertically oriented, for the most part resembling and associated with the vegetative mycelium. Clear, unicellular and often ornamented spores (conidia) develop terminally, either in short chains or singularly, and measure 3-5 x 4-7 microns. 

Microscopic Characteristics Conidiophores compaot, short and radiating from cushion shaped cells called sporodochia and from which dark, one celled, round spores (oonidia) arise or with which they are associated. The conidia are typically reticulated or ornamented with small spine-like projeotions, measuring (5) 1 5-25 (50) microns. These reticulated conidia appear to be composed of several tightly interoonneoted cells. 

Incubate at 25°C (77°F) for 3-5 days and examine. Where asco-spores are seen, note numbers per ascus (mother cell), their shape, surface ornamentation, and color, if any. Also note shape of mother cell (ascus). 

Vitt (1981) commented on the correlation between loss of function, and fusion or reduction in the peristome, concluding that loss of function precedes peristome reduction or fusion in xerophytic environments. However, observation of all species of African Entodontaceae proved that these peristomes retain some residual function. Even in those genera with extreme peristome reduction the remaining exostome remnants respond to changing levels of humidity, and when closed prevent spore release. Exostome function is related to both the internal anatomy and chemistry of the exostome and the form of the external ornamentation. 

There is no experimental evidence on the way in which the fine details of structure and ornamentation of the peristome may affect its function. Shaw and Robinson (1984) suggest that variation in the detail of the peristome ornamentation and structure may alter the air vortexes at the mouth of the capsule and thus modify spore release. 

Ornamentation of spores is exceedingly rare among lichenized fungi. It is of specific value above all in the Caliciales, where in various genera it is a very good species character (see Tibell, 1971), and sometimes in Physconia and Melaspilea. 

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