256 MANUAL OF POISONOUS PLANTS 



PLECTASCINEAE 



Generally saprophytic fungi with a well developed mycelium, either buried 

 in the sub-stratum or superficial. Reproduction sexual or asexual ; asci either 

 borne directly on the mycelium or in closed fruiting bodies, called perithecia. 



ASPERGILLACEAE 



Peridium thick; perithecia small; the sexual reproduction may be seen 

 from the development as it occurs in the Blue Mould (Penicillium). 



Penicillium. Link 



A branched septate mycelium; conidiophores with septa, numerous branches 

 near the apex; contains small flask-shaped sterigmata; spores borne in chains; 

 conidiophores sometimes in bundles, as in the old Coremium; asci develop in 

 poorly-lighted places in a sclerotium-like body. 



Penicillium glaucum. Link. Blue Mould 



At first a white mycelium spreads over the surface or through the sub- 

 stratum; the mycelium, through an enzyme action, undoubtedly, dissolves the 

 starch; raised masses are formed on the surface, which consist of masses of 

 mycelium thread strands; the strands send out lateral branches from the end 

 of which a whorl of short branches appears, which give rise to one or more 

 whorls; from the ultimate branches a chain of small spores is produced, the 

 last one on the chain being the oldest. 



The ascospores have not been found in corn, but occur in poorly lighted 

 places and are produced in the absence of oxygen. The spores produced in 

 chains germinate when the required amount of moisture and heat is present, 

 so that unlimited numbers of generations may proceed from a single spore. 

 These spores also preserve their vitality for a considerable length of time. 



Brefeld has shown that they will germinate though kept in a dry place for 

 several years. The organism grows at various temperatures, from near the 

 freezing point to a considerable heat. It also resists antiseptics. It is one of 

 the most troublesome fungi in stored fruit. 



Penicillium glaucum is an organism which contains diastase, maltase, emulsin 

 and a ferment which inverts cane sugar. Calcium oxalate is deposited in the 

 perithecia. Under certain conditions mannite is said to be produced. When the 

 Penicillium glaucum occurs in grape must it delays fermentation. 



Distribution. The common blue mould is widely distributed in nature and 

 is contained in a large number of the spores which drop in on fruits and decay- 

 ing bodies and there germinate and produce fruiting bodies. 



Poisonous properties. This fungus certainly ;s not pathogenic. It is widely 

 distributed on decaying fruit; it has been suspected, in several instances, of 

 being poisonous, but there is no evidence to support the supposition that this 

 is the case or that it produces toxic substances. Under certain conditions it may, 

 possibly, produce mycotic stomatitis. It has been found in sputum, nasal 

 secretions, and in the stomach, but these cases are without special significance. 



Penicillium minimum. Siebenmann 



Mycelium at first white, flocculent, changing to blackish green when spores 

 are formed ; conidiophores slender, branching, bearing a chain of spores from 

 2-3 /j. in diameter. 



