222 MANUAL OF POISONOUS PLANTS 



pseudoperidium ; uredospores 1-celled occurring singly or in groups with or 

 without pseudoperidium; paraphyses present, teleutospores 1-4-celled, closely or 

 loosely united in the plant underneath the epidermis ; Calyptospora Goeppertiam 

 occurs upon the huckleberry and bluejjerry, {Vaccinium) connected with the 

 Aecidium columnare, a very troublesome parasite upon Abies. The Melampsora 

 populina occurs on the cotton-wood, the cotton-wood rust forming red sori on 

 the leaf of the cotton-wood, with waxy incrustations. The other troublesome 

 parasite, the Chrysomyxa Rhododendri occurs upon Rhododendrum. There are 

 about 100 species in the family. 



Coleosporium. Lev. 



Teleutosori forming flat waxy masses in the leaf; teleutospores composed 

 of several vertical cells enclosed in a thick transparent membrane; each cell 

 germinates by a single undivided promycelium which produces at the end a 

 single sporidium; uredosorus reddish or orange, powdery; spores spherical or 

 sub-spherical, ovate, elliptical, oblong or cylindrical, produced in basipetal chains. 

 A small genus of 30 species. 



Coleosporium Solidaginis (Schw.) Thtim. Golden Rod Rust 



Uredosori rounded, soon pulverulent and scattered, orange spores in short 

 chains, spherical, oblong, or sub-cylindrical spiny, 20-35 x 15-20 /*; the teleu- 

 tosori at first orange, becoming red, flat often confluent forming waxy crusts; 

 Teleutospores cylindrical or somewhat clavate generally 4-celled 60-70x15x25 ^ 

 occasionally longer. 



Distribution and hosts. Found in various Compositae, notaWy SoUdago 

 canadensis, S. serotina, etc., Vernonia novehoracensis and Sonchus. Occurs in 

 both Europe and America. 



Poisonous properties. Suspected of being injurious to horses; possibly 

 produces stomatitis. Referred to at length under Golden Rod. 



PUCaNIACB^B 



Teleutospores with a short or long pedicel; spores single or in groups; 

 spores one or more celled; frequently interspersed with paraphyses; spore mass 

 powdery or gelatinous; sporidia arising either from the promycelium or from 

 a similar sterigma after segmentation of the spore contents; aecidia with or 

 without pseudoperidia; uredospores 1-celled, arising from the conidiophores. 

 Includes the Gymnosporangium macropus which produces its aecidium stage 

 on the apple and the teleuto stage on the red cedar, the cedar apple gall with 

 its long gelatinous horn being characteristic; and various aecidia connected 

 with various rusts. Many species have a well marked alternation of generation, 

 an aecidium on one host and the uredo and teleutospores on another host. The 

 Hemileia vastatrix produces the coffee leaf disease of Asia, Phragmidium svb- 

 corticum, the rose rust. This large family contains 1500 species. 



Recent investigations on the subject of the fertilization and reproduction 

 in the rusts have been made by Profs. Olive, Blackman, Christman, Holden and 

 Harper, and others. These studies seem to indicate that fertilization occurs, 

 but that this fertilization is not, as was thought by the older writers, to be com- 

 pared with that which occurs in some of the Ascomycetes. The older view 

 was that the spermogonia were male organs and form a strictly morphological 

 standpoint comparable to the structures of like character found in that group of 



