16 ACOTYLEDONS. FUNGI. PuCCinia. 



Hab. la the fructification of grasses, especially of wheat, barley, 

 and oats. 



This is a fungus which does considerable injury to corn, particularly 

 to the wheat crops by destroying the grain and converting it wholly 

 into black dust, known by the name of brand, dust brand, smut, 

 burnt corn, &c. It has, however, no scent like the following, and 

 does not affect the whole mass in the thrashing. 



13. U. Ca/ie5, sponiles minute inclosed in peridia of a brown- 

 ish black colour, and filling the grain with a fetid powder. 

 U. sHophila, Ditmar in Sturm's Deiitsch. Fl. ivth a fig. 



Hab. The inside of the grains of wheat. 



It is not a little remarkable that I can find no account of this little 

 fungus, the most injurious perhaps of all the tribe to the agricul- 

 turist, in any botanical work but that above quoted ; except, indeed, 

 that it is said in the Nouveau Dkt'ionnaire d'Hist. Nat. now pub- 

 lishing, to be the Uredo Carles of Decand. ; but I know not in 

 what work of that author, for most assuredly it is not in the Flore 

 Frangoise. It is, according to Ditmar, a distinct genus from the 

 foregoing, inasmuch as its sporules are included in a sort of capsule 

 or peridium, which he calls sporidium. It affects the kernel of wheat 

 in a difterent manner from that, not appearing externally, though 

 its presence may be known by the somewhat smaller, yet inflated, 

 appearance of the grain, and its darker colour. When broken it 

 is greasy to the touch, and has a fetid smell, which may be aptly 

 compared to that of Chenopodhun olidum. It is not merely that a 

 vast quantity of grain is destroyed by the action of th'ia fungus upon 

 each separate kernel it attacks, but, in the operation of thrashing, 

 the injured kernels are broken, and the soil and smell are communi- 

 cated to the whole sample, 



21. PUCCINIA*. 

 Peridia having dissepiments, stipitatc. 

 Parasitic on the stalks or leaves of plants. 



* A German author, M. Strauss, unites, I think with propriety, the genera 

 Siilbospora and Pucciiiia with Urcdo, which he subdivides in the following 

 manner. 



UREDO. 



Pulverulent Fungi. Capsules {Thec(je,Sporul(jc) collected into a pulverulent 

 cluster, for the most part covered with the epidermis. 



A. Ftmgi growing ujmi wood. {Colour black.) Stilbospora. 



B. Fungi parasitic on the fructifications of plants. {Colour black.) Ustilago. 



C. Fungi parasitic upon leaves. 



1, Capsules desi'tuie of dissepiments. 



a. Colour u-hilc. Albugo. 



b. Colour yellowish. Rubigo. 



c. Colour obscure, becoming black. Nigredo. 



2. Capsules furnished xcith dissepiments. Puccinia. 



