528 FLORA. 



3. PROSOPIS L. 



Trees or shrubs often with spines in the axils, with 2-pinnate leaves and small 

 spicate or capitate flowers. Calyx with 5 short teeth. Petals 5, valvate, distinct, 

 or connate below. Stamens 10, distinct; filaments long. Ovary often stalked, 

 many-ovuled; style slender or filiform; stigma very small. Pod linear, compressed, 

 leathery, indehiscent, the mesocarp spongy or dry. Seeds flattened. [Ancient 

 name for some very different plant.] About 15 species, natives of warm and tropi- 

 cal regions. Besides the following, 2 or 3 others occur in the southwestern U. S. 



i. Prosopis glandulosa Torr. PRAIRIE MESQUITE. (I. F. f. 2O32a.) A 

 shrub, the axils usually with a pair of sharp spines. Leaves petioled, with 2 

 spreading short-stalked pinnae, each of numerous sessile pinnules; pinnules linear 

 or linear-oblong, entire, mostly mucronulate, firm, veiny, 1-5 cm. long, 2-4 mm. 

 wide; spikes axillary, peduncled, densely many-flowered, 5-13 cm. long; calyx 

 campanulate ; petals 2-4 times as long as the calyx ; ovary villous; pods linear, 

 stipitate, 1-2 dm. long, 8-12 mm. wide, constricted between the seeds. Kans. 

 to Tex., Ariz, and Mex. April-June. 



4 . MORONGIA Britton. 



Perennial herbs, or shrubs, mainly prostrate or procumbent, armed with re- 

 curved prickles. Leaves bipinnate, usually sensitive; leaflets numerous, small; 

 stipules setaceous. Flowers regular, small, 4-5 -parted, pink or purple, perfect or 

 polygamous, in axillary peduncled heads or spikes. Stamens usually 8-12, dis- 

 tinct or united at the base; anthers all alike. Ovary nearly sessile; ovules oo . 

 Pod linear, acute or acuminate, spiny all over, at length 4-valved, several-seeded. 

 [Named in honor of the late Rev. Thos. Morong, a contributor to this work.] 

 About 10 species, natives of warm and tropical America, I in tropical Africa. 



Leaflets elliptic, strongly veined. i. M. unctnata. 



Leaflets linear-oblong, scarcely veined. 2. M. angustata. 



1. Morongia uncinata (Willd.) Britton. SENSITIVE-BRIER. (I. F. f. 2031.) 

 Decumbent, 6-12 dm. long. Stem, branches, petioles and peduncles thickly 

 armed with hooked prickles 1-2 mm. long; stem grooved and angled; leaves 

 petioled ; pinnae 4-8 pairs, distant; leaflets 8-15 pairs, obliquely elliptic, thick, 

 obtusish and mucronate at the apex, inequilateral and rounded at the base, slightly 

 ciliate on the margins, 4-8 mm. long; heads globose, very dense, 1.5-2.5 cm. in 

 diameter; flowers pink; pods terete, very densely spiny, about 5 cm. long. In 

 dry soil, Va. to 111., S. Dak., Fla. and Tex. May-July. 



2. Morongia angustata (T. & G.) Britton. NARROW-LEAVED SENSITIVE- 

 BRIER. (I. F. f. 2032.) Similar to the preceding species. Pinnae 3-6 pairs; 

 leaflets numerous, thin, acutish or obtuse, not mucronate or but very slightly so, 

 not at all reticulated, 3-6 mm. long; peduncles shorter than the leaves; heads 

 densely flowered, 1-1.6 cm. in diameter; flowers pink; pods linear, sparingly or 

 densely spiny, 5-13 cm. long. In dry soil, Va. to Fla., Tenn. and Tex. \Mimosa 

 microphylla Dry and. ?]. 



Family 15. CAESALPINIACEAE Kl. & Garcke. 

 Senna Family. 



Trees, herbs or shrubs, with alternate simple or compound mostly 

 stipulate leaves. Flowers mostly clustered and perfect, sometimes 

 monoecious, dioecious or polygamous, nearly regular, or irregular. 

 Calyx mostly of 5 sepals or 5-toothed. Petals usually 5, imbricated, and 

 the upper (unpaired) one enclosed by the lateral ones in the bud. Sta- 

 mens 10 or fewer in our genera, the filaments distinct, or more or less 

 united. Ovary i -celled, i-many-ovuled. Fruit a legume, mostly de- 

 hiscent into 2 valves. Seeds with or without endosperm. About 90 

 genera and 1000 species, mostly of tropical distribution. 



Trees or shrubs ; leaves simple; corolla irregular, apparently papilionaceous, but the 

 lateral petals enclosing the upper one. i. Cercis. 



