146 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Zygophyllidium exstipulatum (Engelm.) Wooton & Standley. 
Euphorbia exstipulata Engelm. in Torr. U. 8. & Mex. Bound. Bot. 189. 1859. 
ANACARDIACEAE, 
Rhus choriophylla Wooton & Standley, sp. nov. 
Low shrub, 1 or even 2 meters high, with few branches; stems stout, the 
younger ones purplish, finely pubescent; leaflets 3 or 5, ovate, abruptly acumi- 
nate, 30 to GO mm. long, thick and coriaceous, glabrous, pale green, rather dull 
on the upper surface, mostly unequally rounded at the base; rachis finely 
puberulent; terminal leaflet larger and broader than the others; flowers in 
dense panicles much shorter than the leaves; bracts ovate, acuminate, densely 
pubescent; flowers almost sessile; fruit spherical, 5 mm. in diameter, orange, 
densely hirtellous, 
Type in the U. S. National Herbarium, no. 560279, collected in Guadalupe 
Canyon, on the Mexican boundary, near the southwest corner of New Mexico, 
August 16, 1892, by Dr. E. A. Mearns (no. 699). 
ADDITIONAL SPECIMENS EXAMINED: Guadalupe Canyon, 1893, Mearns 2524; 
Pena Blanca, November 30, 1901, Mae Gilmore; San Andreas Mountains, 
February 9, 1902, Wooton. 
In addition to the specimens cited, we have seen others from western Texas, 
southern Arizona, and northern Chihuahua. 
Evidently this is closely related to R. virens Lindh., but the vegetative 
characters are noticeably different, the leaflets being uniformly broader, rounded 
at the base, abruptly acuminate, glabrous, and of about the same shade of pale 
green on both surfaces. The leaflets, too, are fewer. 
ACERACEAE. 
Acer brachypterum Wooton & Standley, sp. nov. 
Tree of medium size, with spreading, smooth, brownish, slender branches; 
young twigs finely and densely pubescent; petioles usually shorter than the 
blades, mostly densely and finely velvety pubescent even in age; leaf blades 
averaging 5 cm. long and 6 to 8 em. broad, 5-lobed, all the lobes divergent, the 
two basal ones much smaller than the others or sometimes wanting; leaves 
cordate of truncate at the base, dull green and glabrous above, paler and 
pubescent beneath, thick, the lobes triangular-lanceolate or oblong-lanceolate, 
entire or with one or two low, rounded, lateral lobes, acutish; flowers not seen ; 
calyx persistent ; inflorescence short and few-fruited; pedicels slender. 20 to 35 
mm. long, pubescent; body of the fruit turgid, glabrous, strongly reticulate, the 
wings small, 15 mm. long and 10 mm. wide or smaller, glabrous, strongly veined, 
reddish. 
Type in the U. S. National Herbarium, no. 560270, collected in the San Luis 
Mountains, July 19, 1892, by Dr. E. A. Mearns (no. 535). 
ADDITIONAL SPECIMENS EXAMINED: San Luis Mountains, 1892, Mearns 71, 
569; San Luis Mountains, alt. 1.800 meters, October 1, 1893, Mearns 2481. 
A species near A. grandidentatum, but the leaves have very different lobes 
and are more densely pubescent, and the wings of the fruit are much shorter. 
_A note by Doctor Mearns on one of the sheets says: “This is the hard maple 
of this region. I also saw it in the Mogollon Mountains of Arizona, where the 
leaves turned red in October. Usually it is a small tree in ravines or canyons 
of the mountains. There is a photograph of the tree in the Report ' which grew 
*Report of the Boundary Commission upon the Survey and Re-marking of 
the Boundary between the United States and Mexico west of the Rio Grande, 
pl. facing p. 15. 1898, 
