206 THE LOWER FUNGI— PHYCOMYCETES 



The fungus attacks the pod especially, producing a woolly white 

 growth of sporangiophores over its surface (Fig. 77, c). The 

 oospores are developed in the seed of the host. Leonian (1925) 

 regards the species as a variety of Phy. infestans. 



Phyfophfhora omnivora de Bary (1881) represents the merging 

 and treatment under a new name of three previously described 

 species. These include Peronos'pora cactorum Lebert & Cohn 

 (1871), described as causing a rot in two species of cactus, 

 Perofwspora fagi Hartig (1876), cause of damping-off of beech 

 seedlings, and Peronospora sempervivum Schenk (1875), parasitic 

 on Sempervivum. The new specific name omnivora was used by 

 de Bary without regard to priority, and alludes to the occurrence 

 of the species on many hosts. Schroter (1889) revived the 

 older name cactorum, and is responsible for the binomial, Phy~ 

 tophthora cactorum (Lebert & Cohn) Schroter. At present, 

 in the absence of uniformity of opinion concerning specific 

 limits, Phy. cactorum, Phy. fagi, and Phy. om^iivora may be found 

 in the literature treated as distinct species or merged in various 

 ways with each other or with still other forms. Leonian (1925) 

 recognizes Phy. omnivora, but merges with it Phy. colocasiae, 

 Phy. palmivora, Phy. faheri, Phy. parasitica, Phy. terrestria, 

 and Phy. parasitica var. rhei, while recognizing Phy. cactorum as 

 a distinct species. In England a rot of apples and pears is 

 attributed by Wormald to Phy. o7nnivora. Drechsler states 

 that the species is the cause of a foot rot of lilies, and other authors 

 report it on ginseng (Rosenbaum, 1915), strawberries, rhubarb, 

 and other plants. 



Phytophthora palmivora Butler (1919) cause of the well known 

 bud rot of Palmyra palms in India is, perhaps, not specifically 

 distinct from Phy. meadii McRae (1918 a, b) and Phy. faheri 

 Maublanc (1909) reported from Hevea (rubber), cocoa, coconut, 

 and other tropical plants. See Gadd (1927). 



Phytophthora erythr aseptic a Pethybridge (1913 6; 1914) causes 

 a pink rot of potato tubers and has been reported from Ireland, 

 England, Holland, Switzerland, and Java. 



Additional published species are Phytophthora agaves Gandara 

 (1909), PA?/, alia Sawada (1915), P/i?/. arecae Pethybridge (1913 h), 

 Phy. capsici Leonian (1922), Phy. carica (Hara) Hori (in Sawada, 

 1919), Phy. citri Rau (1916), Phy. cinnamomi Rand (1922), Phy. 

 cryptogea Pethybridge & Lafferty (1919), Phy. colocasiae 

 Raciborski (1900), Phy. fici Hori (1915 in Japanese: see Sawada, 



