344 BOTANICAL GAZETTE [MAY 
is based T. potosanum Loja. A duplicate type is in the U. S. National 
Herbarium. 
The following specimens from central Mexico differ from typical T. mexi- 
canum in having larger flowers, more pubescent stems, and blunter leaflets, and 
are more spreading in habit. They may represent a variety, but scarcely more. 
Mexico (state): hills near Ozumba, 2400™ alt., Pringle (no. 9775), Nov. 8, 
1902; Flor de Maria, Pringle (no. 3238), Sept. 4, 1890; Rose and Painter (no. 
7816), Oct. 13, 1903. 
Trifolium Nelsoni, sp. nov.—Fig. 11.—Related somewhat to 
T. mexicanum but scarcely resembling it. Stems spreading and 
ascending from a perennial root, minutely 
pubescent, about 50°™ long or less: sti- 
pules ovate-lanceolate, green, rigid and 
the lower scarious, aristate-acuminate, 
entire, 15 to 20™™ long; leaflets ovate- 
lanceolate to elliptic-oblong, sparingly 
pubescent and pale beneath, green and 
glabrous above, usually with a whitish 
V-shaped blotch on the upper surface, 
apex acute or blunt, callous-tipped, mar- 
gins inconspicuously repand-denticulate ; 
petioles of the lower leaves 2 to 4 times 
the length of the leaflets: peduncles dense- 
ly woolly-pubescent toward the summit, 
: often 15 to 20°™ long; heads depressed- 
Fic. 11.—Trijolium Nelsoni globose, 20 to 40-flowered, flowers sub- 
i tended by subulate filiform bracts, 3 to 
5™™ long; pedicels none or very short: calyx-tube 1o-nerved, about 
1.5™™ long, the subulate green teeth 4.5 to 5™™ long, subequal: 
corolla yellowish; banner 8 to 10™™ long, orbicular-obovate, slightly 
retuse at the apex or rounded; wings and keel shorter but relatively 
broad. . 
Vicinity of La Parada, Oaxaca, E. W. Nelson (no. 1016), Aug. 19, 1894 
(type in the U. S. National Herbarium). Remarkable for the extremely broad 
petals. 
Trirotium Patmerr S. Wats., Proc. Am. Acad. 11:132. 1876. 
Guadalupe Island: Palmer (no. 26, 1875), type in Gray Herbarium; a dupli- 
cate type in herbaria of Professor Greene and Columbia University; Greene 
Apr. 21, 1885; Palmer (no. 859), 1889; Dr. F. Franceschi, 1893. 
