1904] BRIEFER ARTICLES 219 
or expanded, even deflexed and almost involute at times, and wavy or 
lobed ; entirely white when young, shading in age into ochraceous- 
buff, ochraceous, and even orange above, remaining more pallid below; 
hygrophanous when moist, and slightly viscid or glutinous ; flesh 
very soft, almost of waxy consistency, composed of very loosely woven 
mycelium in the center, becoming denser at the surface. Stem solid, 
equal or slightly broadened upward, 0.5—1™™ in ‘diameter, white prui- 
nose becoming pubescent with scattered white hairs at base. The 
hymenium surrounds the upper two-fifths to one-half of the length of 
the fruit body; basidia clavate, 18-24 X 4p, 4-spored, sterigmata up to 
4p in length; spores broadly elliptical to subglobose, smooth, white, 
3-4p; cystidia white, numerous, often 60-70 X 4-6pn, usually curved 
and irregularly swollen toward the base where they arise from the 
trama, extending beyond the basidia only when young and by 2-4p, 
thin-walled and containing substances which blacken with osmic acid. 
Type in Cornell University Herbarium, no. 15,445, collected from 
very rotten twigs and leaves of deciduous trees and conifers, but only 
under prostrate branches of Zaxus canadensis, in Fall Creek gorge, 
Ithaca, N. Y., between October 19 and November 19, 1903.— CHARLES 
Tuom, Cornell University. 
NOTES ON SOUTHWESTERN AND MEXICAN PLANTS. 
I. THE INDIGENOUS CENTAUREAS OF NORTH AMERICA. 
THE first species of the genus Centaurea indigenous to North 
America was published by Nuttall in 1821, as C. americana. The species 
was originally collected in Arkansas, where it was said by Nuttall to 
grow “on the banks of streams, and in denudated alluvial situations, 
throughout the plains or prairies of the upper part of Arkansas 
territory.” 
Sprengel in the Supplement of the fourth volume of the Systema 
vegetabilium quite arbitrarily makes a new combination for Nuttall’s 
plant, namely C. Wuftallii, having himself previously, in the third 
volume of the Systema, p. 407 (1826), used the combination C. amert- 
cana for a Peruvian plant, which is very different from the North 
American species. Further, in 1831, D. Don, in Sweet's British flower 
garden 2: pl. 51, characterizes and illustrates the species published by 
Nuttall under the name Plectocephalus americanus. Both of these com- 
binations, C. Wuttallit and Plectocephalus americanus, are merely altered 
names for Nuttall’s species and are invalidated by all present rules of 
