582 Long : Local Distribution and Occurrence of 



spreading the fungi rapidly over wide areas. In this manner wheat 

 rust becomes very virulent and destructive. 



The majority of the introduced species of the cereals and of 

 other plants are often attacked by the ephemeral fungi, to which 

 they are subjected in their older habitat. Such are the various 

 rusts and smuts infesting wheat, oats, corn, clover. As a rule, 

 the parasitic fungi of this vicinity are very limited in number of 

 species. In this group come two species of Gymnosporangiiiwi 

 G. macropus on Jiuiiperus Virginiana, the other a new form found 

 on mountain cedar, Sabina sabinoides, which does not form galls 

 or " apples/' but the teleutospore masses break out directly from 

 the stem or leaf in rows, like the teeth of a comb, common during 

 March on the mountain cedar, but never found on J. Virginiana. 

 Several species of Pitccinia, one on Berberis trifoliata (barberry), 

 ,aecidium stage, very rare, stages I, II, III, and spermagoma 

 present, only one infected bush found. A species of Uromyces on the 

 mesquite (Prosopis juliflord), forms large oblong-cylindric galls or 

 " apples " on the petioles and petiolules, about 2 cm. long by 5 cm. 

 thick, covered with oblong brown sori, which are filled with 

 uredospores ; not common, only infesting an occasional tree ; II 

 and III stages found on leaves in July, after " apples " have fallen. 

 Another fungus attacks the under side of the mesquite leaves, es- 

 pecially those of the small bushes. 



Of the saprophytic fungi we find several well-marked types. 

 Group I, includes those inhabiting various kinds of dung. These are 

 few in number, but have a wide range as to time and place of oc- _ 

 currence, their peculiar habitat producing the environments neces- 

 sary to a quick growth, therefore on the slightest rain or even dew 

 they send up their organs of reproduction and disseminate their 

 spores. Species of Ascobohis, Lasiobolus, Coprinus, Psilocybe and 

 Stropharia form some of this group. 



In Group II are those growing in the cedar brakes beneath the 

 trees ; the cedars especially form at their bases a mass of decaying 

 debris, which persists year after year, and thus attains a thickness 

 of several inches. This being shaded by the overhanging boughs, 

 produces and retains a humus, thereby securing more favorable 

 conditions for fungal growths than in the open, unshaded places. 

 We therefore find quite a diversity of species in such localities. 



