2 5 6 



MIMOSACEAE. 



[Vol.. II. 



i. Morongia uncinata (Willd.) Britton. Sensitive-brier. (Fig. 2031.) 



Schrankia uncinata Willd. Sp. PI. 4: 1043. 1806. 

 Mimosa Intsia Walt. Fl. Car. 252. 1788. Not L. 1753. 

 Morongia uncinata Britton, Mem. Torr. Club, 5: 191. 



1894. 



Herbaceous, perennial, branched, decumbent, 2- 

 4 long. Stem, branches, petioles and peduncles 

 thickly armed with hooked prickles %."-\' f long; 

 stem grooved and angled; leaves petioled; pinnae 

 4-8 pairs, distant; leaflets 8-15 pairs, obliquely el- 

 liptic, thick, obtusish and mucronate at the apex, 

 inequilateral and rounded at the base, slightly cili- 

 ate on the margins, strongly marked with few eleva- 

 ted veins beneath, 2 // -4 // long; heads globose, very 

 dense, 8"- 12" in diameter; flowers pink; pods 

 terete, very densely spiny, about 2' long. 



In dry soil, Virginia to Illinois and Nebraska, south 

 to Florida and Texas. May-July. 



a. Morongia angustata (T. & G.) Britton. 



Narrow-leaved Sensitive-brier. 



(Fig. 2032.) 



Schrankia angustata T. & G. Fl. N. A. i: 400. 1840. 

 Morongia angustata Britton, Mem. Torr. Club, 5: 191. 1894. 



Similar to the preceding species. Pinnae 3-6 pairs; 

 leaflets numerous, linear-oblong, thin, acutish or ob- 

 tuse, not mucronate or but very slightly so, very ob- 

 scurely veined, not at all reticulated, \ l /t' f -^" long; 

 peduncles shorter than the leaves; heads densely flow- 

 ered, 5"-8" in diameter; flowers pink; pods linear, 

 sparingly or densely spiny, i'-$ f long. 



In dry soil, Virginia to Florida, west to Tennessee and 

 Texas. 



Family 47. CAESALPINACEAE Kl. &Garcke, Bot. Erg.Wald. 157. 1862. 



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. Stamens 10 or fewer in our genera, the fila- 

 ments distinct, or more or less united. Ovary i -celled, i-many-ovuled. Fruit 

 a legume, mostly dehiscent 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. 



Herbs (all our species); flowers perfect; leaves pinnate or bipinnate; corolla nearly regular. 



Leaves pinnate, not punctate. 2. Cassia. 



Leaves bipinnate, glandular-punctate. 3. Hoffmanseggia. 



Trees; leaves pinnate or bipinnate; flowers dioecious or polygamous. 



Receptacle short; stamens 3-5; pod flat, elongated. 4. Gleditsia. 



Receptacle elongated; stamens 10; pod oblong, woody. 5. Gymnocladus. 



i. CERCIS L. Sp. PI. 374. 1753. 



Small trees or shrubs, with simple broad leaves, and pink flowers in short lateral fascicles 

 borne on the twigs of preceding seasons. Calyx somewhat oblique, broadly campanulate, 



