Kelley — 28 — Mycotrophy 



reports for Thuopsis dolobrata and for the Incense cedar, Lihrocedrus, 

 which last Yeates (1924) says contains a fungus similar to that in 

 taxads. Thuja stands in a better position, being a more abundant 

 tree in the cool temperate zone where most mycorrhizal students have 

 lived. T. occidentalis and T. orientalis are both well studied while T. 

 plicata and T. Standishii are reported as mycorrhizal. Two recent 

 papers have cited the genus, — Klecka & Vukolov (1935) and 

 DoMiNiK (1937). Taxodium distichum has been listed as having en- 

 dotrophic mycorrhizae but Sequoia — more attractive to curiosity — has 

 been more studied. Both species of Sequoia possess endotrophic 

 mycorrhizae, it would appear, and according to Strasburger, root- 

 hairs are entirely wanting. Oddly enough, it is only European material 

 of Sequoia that has been investigated while Calif ornians neglect their 

 most famous tree. Crypfoineria is reported mycorrhizal in Europe : 

 VON TuBEUF found root-hairs wanting in C. japonica although he 

 notes that Klebs found sparse hairs on seedlings, which hairs were 

 sloughed ofif with the outer cell layer, Mimura (1933), working at 

 TokyO', states that mycorrhizae are wanting on this species when 

 planted at the Experiment Station but were found on roots that had 

 grown from the pots into the ground. Cunninghamia, the China fir, 

 is reported mycorrhizal by Noelle (1910) and by Yeates (1924) ; 

 Sciadopitys, the monotypic Umbrella pine, by Noelle and by Laing 

 (1923), the last describing the histology in some detail. 



Four species of Araucaria are termed mycorrhizal. Janse com- 

 pared its rootlets to those of Podocarpus but thought they were rather 

 larger. Of modern writers we may note Rayner (1938) who in a 

 review states that A. Cunninghamii grew in Nyassaland without inocu- 

 lation of the soil ; Young (1938) found that lime-induced chlorosis in 

 this Hoop-pine was eliminated from some Queensland nursery beds 

 by sulphur applications, and the same author found by pure culture 

 experiments that its seedlings produced endotrophic mycorrhizae when 

 grown in association with the fungus Boletus elegans and failed to 

 develop in the absence of a mycorrhizal fungus. 



The genus Abies has not proved attractive to our students although 

 it appears to be mycorrhizal and material is abundant. Fifteen species 

 of the genus are cited as mycorrhizal but without detailed description 

 and with no details of physiological relationship. Of recent workers 

 we may cite Dominik (1937) who notes three exotic species mycor- 

 rhizal in Poland; Colla (1931) who found three Basidiomycetes on 

 A. alba in Italy; Tazoye (1940) who cites A. Mayriana as mycor- 

 rhizal in Japan; Henry (1936) who says that dwarfed A. lasiocarpa 

 in the mountains of Utah is an excellent mycorrhizal host (Mc- 



