THE GENUS ENDOGONE 
GEO. F. ATKINSON 
Cornell University 
The genus Endogone was founded by Link in 1809, and for more 
than a century its life history and taxonomic relationship have re- 
mained very obscure. Notwithstanding this obscurity in relationship 
and development, the structure of the mature plants is so simple and 
characteristic, that comparatively few species have been accredited 
to the genus which do not belong here. The fruit bodies are pulvinate, 
rounded to reniform or irregular. In size they vary from 2-4 mm. 
up to 2-3cm. In life relation they are saprophytes. In habitat they 
are hypogeous, epigeous or epixylous; and occur under or on the 
ground, among or underneath fallen leaves, among the rhizoids of 
mosses or roots of ferns, on dead wood, on sphagnum or other mosses. 
In color they are whitish to yellow, brown or blackish. Approximately 
seventeen species are known. The genus is cosmopolitan in distri- 
bution. Species are known from Europe (including European Russia), 
Ceylon, Tasmania, North America, Central America, South America 
and the Fiji Islands. 
General structure of the fruit body.—There is a peridium of slender, 
interwoven hyphae formed by the terminal branchlets of the hyphae 
which spring from the basal region, branch profusely and radiate to 
the periphery. The interior constitutes the “‘gleba,’’ the base or 
central portion of the ‘‘gleba’’ is sometimes hollow or of less density 
than the broad peripheral zone. The “gleba”’ is usually packed with 
numerous, large thick walled “resting spores,’’ oval, elliptical, or 
spherical in form, and yellowish, grayish or dark brown in color 
according to the species. These ‘‘resting spores’? are 40-100 w in 
diameter, are packed among the hyphae, and terminate certain 
branches. They have been termed spores, sporangia, ampullae, or 
asci, the latter term apparently having the preference, since it is 
employed by a majority of writers. Several large elliptical spores in 
an ‘‘ascus’”’ have been described in one species (Endogone pisiformis), 
a single large spore! in an ascus in another species (EZ. reniformis), 
and numerous minute spores in an ascus in several species. It is 
’ 
1 The spores in this species are probably the ordinary ‘resting spores,’’ the 
‘“‘asci’’ of authors, for Bresadola (1896, p. 297) says that neither the asci nor their 
mode of dehiscence was seen. 
2 1 
