372 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
This species is closely related to Ustilago macrospora. It differs 
from Ustilago striaeformis in having larger more prominently ver- 
rucose spores. Because of its relationship to these species and its 
general appearance, it is considered here as an Ustilago rather than 
a Tilletia. The writer has not seen the form on Calamagrostis 
Pickeringii though it more probably belongs here than under 
Ustilago striaeformis. The germination of this species, apparently, 
has not been reported. 
Ustilago macrospora Desm. 
Ustilago macrospora Desm., PI. Crypt., n, 1727. 1850. 
Tilletia serpens Karst., Eung. Fenn., 599. 1866. 
Tilletia aculeata Ule, Verh. Bot. Ver. Prov. Brand., 25: 213. 1884. 
Exsiccati: Ustilago macrospora Desm., on Elymus sp., Ell., Ev., & 
Barth., Fungi Col., 1900. 
Sori in leaves and glumes, generally showing as linear striae, but 
often more or less merged, at first covered by epidermis, but this 
rupturing and disclosing black brown dusty lines of spores ; spores 
medium to dark reddish brown, chiefly ovoid to spherical or occa¬ 
sionally somewhat irregular and more elongated, coarsely verrucose, 
at circumference usually showing the projections as tinted blunt 
scale-like appendages, sometimes even semi-reticulated, 12-19 p in 
length. 
Host: Agropyrum repens , la., Mass., Wise.; A. spicatum , Ore.; 
A. spicatum var. inerme, Wash.; Agropyrum sp., Utah ; Elymus 
sp., Utah. 
This species is sometimes placed by European botanists with 
forms on Calamagrostis under Tilletia Calamagrostis Fckl. To the 
author it seems distinguished by the coarser papillae which in some 
specimens become even semi-reticulate and by the spores being less 
irregular. However, it is closely related to this species. The syn¬ 
onymy given for Ustilago macrospora is based on an examination 
of authentic exsiccati specimens. The Desmazi&re specimen is said 
to be on Bromus pinnatus, the Karsten on Dactylis glomerata, and 
the Ule on Triticum repens. Concerning Ustilago Salveii on Dactylis 
glomerata Massee says : u The present species has been referred to 
Tilletia striiformis Magpus by various authors, but an examination 
of the type shows it to be quite distinct; it is, however, morpho- 
