SEGREGATES OF RHUS. 137 
S. PUNCTICULATA. Low, stout, rigid, the short branches 
leafy and puberulent, glabrate after the second season, leaves 
small, very short-petioled, subcoriaceous, deep green and 
glabrous above, paler beneath and appressed pubescent on 
the veins, both faces muriculate-punctate; terminal leaflet 
ł inch long, broadly obovate above an acute rather than 
cuneate base, doubly and obtusely crenate: fruit very large, 
scattered, one only from each spike, wholly glabrous, or with a 
few small bristly hairs. 
Union Pass, northern Arizona, 31 May, 1903, N. C. Wilson, 
as in my herbarium. That this species should bein mature leaf 
and fruit in May, and S. elegantula barely in half grown leaf 
and full flower in the same month of the same year, and the 
two occupying stations perhaps 60 or may be 40 miles apart, 
should intimate to the untravelled the wonderful differences of 
climatic and other environment plants find there within a 
small extent of territory. 
S. TRINERVATA. Branches stout, rigid, straight, puberulent 
lenticellate-tuberculate: foliage coriaceous, dark green above, 
lighter beneath, both faces obscurely puberulent, the margins 
and veins beneath sparsely pubescent: terminal leaflet 1 inch 
long, cuneate and entire from about the middle, broadly and 
shortly 3-lobed, the lobes very obtuse, the terminal now and then 
3-crenate, the 3 veins leading to the 3 lobes chiefly conspicuous ; 
lateral leaflets smaller, equal-sided, broadly 5-crenate: scales of 
the small spikes whully villous-tomentose. 
San Francisco Mountain, Ariz., 2 Sept., 1889, F. H. Knowlton. 
S. HIRTELLA. Branches slender, hirtellous-tomentose when 
young, not quite glabrate the second season: leaves small and 
leaflets elongated, soft-pubescent on both faces; terminal leaflet 
quite cuneiform below a short 3-Jobed apex, the middle lobe 
longer than the others and often 3-lobed, all obtuse; laterals 
small and variable, some cuneate-obovate and 3-lobed, others 
oval and quite entire: fruits small, glabrous or with a few small 
bristly hairs. 
Grand Cañon of the Colorado, Ariz., 10 July, 1892, E. O. 
Wooton. 
