101 
loosely appressed pilose and reticulate beneath : pod hirsute-pnberulent or glabrate, 
with rather membranaceous valves and very thick margins (C. herbacea Engelm.)— 
In the mountains west of the Pecos, especially near the Limpia. 
52. PITHECOLOBIUM Martius. 
Trees or shrubs, often spiny, with bi pinnate leaves, flowers in globose 
heads or loose spikes, tubular corolla and long-exserted stamens, and a 
straight or faleate pod trausversely partitioned within, the valves not 
elastically revolute. 
1. P. brevifolium Benth. (HuasILLo.) Shrub, with puberulent branchlets, in- 
florescence and young leaves, and stipular spines: pinne 3 to 5 pairs; leaflets 10 to 
20 pairs, oblong-linear, pale beneath, 4 to 6 mm. long: pod straight, very acute, stipi- 
tate, somewhat membranaceons, 7.5 to 10 cm. long, 12 mm. wide.—Along the lower 
Rio Grande. “The permanent foliage readily eaten by sheep and goats in winter” 
(Havard), 
2. P. flexicaule Coulter. A shrub or small tree, with puberulent inflorescence 
and branchlets, and short stout stipular spines: pinne 1 or 2 pairs (the lower pair, 
if present, much the smaller); leaflets 3 or 4 pairs in the upper pair of pinne, 1 or 
2 pairs in the lower, obliquely elliptical, 6 to 10 mm. long, 4 to 6 mm. wide: pod 
coriaceous, becoming very hard and more or less arcuate, with the thickened edges 
somewhat impressed between the seeds, 10 to 15 em. long, 18 to 25 mm. wide, about 
8 seeded. (Acacia flexicaulis Benth, P. Texense Coulter,)—In the valley of the Rio 
Grande, and an abundant species in northern Mexico, 
ROSACEZR. (Roser FAMILY.) 
Herbs, shrubs, or trees, with alternate mostly stipulate leaves, regu- 
lar flowers, mostly numerous stamens inserted on the calyx, and one to 
many pistils distinct and free or coherent with each other and the 
calyx-tube. 
I. Ovary superior and not inclosed in the calyx-tube at maturity, 
* Calyx deciduous, without bractlets: pistil solitary, becoming a drupe. 
TRIBE I. Trees or shrubs, with simple mostly serrate leaves, 2 ovules (but usually 
& solitary seed), and a terminal style.—PRUNE&, 
1. Prunus. Flowers perfect: lobes of calyx and corolla 5: stone of drupe bony. 
** Calyx mostly persistent: pistils few to many (rarely solitary ), 
+ Calyx without bractlets: ovules 2 to many. 
Tripe II. Shrubs or perennial herbs, with mostly 5 pistils which become 2 to 
several-seeded pods.—Spirara,. 
2. Eriogynia. Low cespitose perennials, with small entire leaves, racemose or 
spicate inflorescence, and 2 to 4-seeded coriaceous pod more or less dehiscent by both 
sutures, 
3. Spireea. Usually erect and more or less diffuse shrubs, with serrate or lobed 
corymbose or paniculate inflorescence, and a 1 to several-seeded pod, which may be 
very tardily dehiscent. 
4. Physocarpus. Shrubs, with palmately lobed leaves, corymbose flowers, and 
inflated membranaceous dehiscent pods. 
TRIBE ITI. Perennials, herbaceous or with biennial soft woody stems, with the 
several or numerous pistils becoming drupelets in fruit.—RUBEa&. 
6 Rubus. Pistils humerous, fleshy in fruit, crowded upon a spongy receptacle, 
