VOL. II.] 



PEA FAMILY. 



313 



i. Zornia bracteata (Walt.) Gmel. 

 Zornia. (Fig. 2169.) 



Anonymos bracteata Walt. Fl. Car. 181. 1788. 

 Zornia bracteata Gmel. Syst. 2: 1096. 1791- 

 Zornia tetraphylla Michx. Fl. Bor. Am. 2: 76. 1803. 



Perennial by a long woody root, glabrous or spar- 

 ingly finely pubescent; stems wiry, prostrate, i-2 

 long. Stipules about 3" long; petioles >^ / -i / long, 

 slender; leaflets 4, oblong, lanceolate, or oblong- 

 obovate, acute at both ends, X /-I/ l n g> or those of 

 the lower leaves obtuse at the apex and shorter; pe- 

 duncles longer than the petioles; spikes several-flow- 

 ered, much interrupted in fruit, 2 / -4 / long; bracts 

 ovate, or broadly oval, 3 // -5 // long, acute or acutish; 

 pod 3-5-jointed, the joints oval, i^ // -2 // long, 

 densely spinulose. 



In dry sandy soil, southeastern Virginia to Florida, 

 Texas and Mexico. May-Aug. 



Arachis hypogaea L,. , the Pea-nut, is occasionally seen 

 as a waif, not permanently established. 



34. MEIBOMIA Adans. Fam. PI. 2: 509. 1763. 

 [DESMODIUM Desv. Journ. Bot. (II.) i: 122. pi. 5, f. /j. 1813.] 



Perennial herbs, sometimes woody at the base, erect, ascending or trailing, with stipellate 

 3-foliolate or in some species i- or 5-foliolate leaves, and usually small flowers in terminal 

 or axillary compound or simple racemes or panicles. Calyx-tube short, its teeth more or less 

 united into 2 lips, the upper one variously 2-toothed, the 3 lower teeth acute or attenuate. 

 Standard oblong, ovate or orbicular, narrowed or rarely clawed at the base; wings obliquely 

 oblong; keel nearly straight, obtuse. Stamens rnonadelphous or diadelphous (9 and i); an- 

 thers all alike. Ovary sessile or stalked; ovules 2-00. Loment flat, sessile or stalked, several 

 jointed, the joints mainly coriaceous and pubescent or muricate, indehiscent or rarely parti- 

 ally dehiscent, readily separable. [Named for Dr. Brandus Meibom, died at Helmstadt, 1740 ] 

 A genus of about 160 species, natives of warm and temperate North and South America, South 

 Africa and Australia. Besides the following, about 20 others occur in the southern and southwest- 

 ern States. Our species are known as Tick-trefoil, or Tick-seed. 



jf Loment not constricted above, deeply constricted below, long-stalked ; leaflets broad. 

 Panicle arising from the base of the plant; peduncle usually leafless. i. M. nudifiora. 



Panicle terminal; leaves crowded at its base. 2. M. grandiftora. 



leaves scattered along the stem. 3. M. pauciflora. 



5f -X- Loment constricted on both margins, more deeply below than above. 



t Stems trailing or reclining. 

 Leaflets orbicular or nearly so. 



Leaflets i' long or less, glabrate, coriaceous. 

 Leaflets i'-z' long, thinnish, usually quite pubescent. 

 Leaflets ovate or oval. 



Corolla whitish; leaves yellowish green; stipules broadly ovate. 

 Corolla purple; leaves dull green; stipules subulate. 



t t Stems erect or ascending. 



Leaves sessile or nearly so; leaflets linear or lanceolate. 

 Leaves petioled. 



Leaflets narrowly linear; joints of the loment usually concave on the back 9. 

 Leaflets broad (except in J/. paniculate, Chapmani). 



1. Joints of the loment notably longer than broad. 



Leaflets obtuse, rough-pubescent, yellowish green. 10. M. canescens. 



Leaflets long-acuminate, scabrate abcve, slightly villous beneath, u. M. longifolia. 

 Leaflets long-acuminate, glabrous, glaucous beneath. 12. M. bracteosa. 



2. Joints of the loment little longer than broad. 



(a. ) Loment distinctly long-stalked in the calyx. 



Plants glabrous, or nearly so (except in M. paniculata pubens). 



Leaflets lanceolate or oblong. 13. M. paniculata. 



Leaflets broadly ovate or oval, glaucous beneath. 14. M. laevigata. 



Plants pubescent or scabrous. 



Leaflets thick, coriaceous, villous and reticulated beneath. 15. M. rhombi folia. 

 velvety-pubescent beneath. 16. M. viridifiora. 

 Leaflets scarcely coriaceous, appressed-pubescent or villous beneath. 



17. M. Dillenii. 



(b. ) Loment sessile in the calyx, or nearly so. 

 Loment-joints 4-7; flowers numerous, showy. 



Leaflets coriaceous, strongly reticulated beneath. 18. M. Illinoensis. 



Leaflets riot coriaceous, scarcely reticulated beneath; loments numerous. 



19. M. Canadensis. 

 Loment-joints 1-3. 



Leaflets scabrous, i'-2' long. 

 Leaflets not scabrous, 5"-io" long. 

 Plant nearly glabrous throughout. 

 Stem pubescent; leaflets and petioles ciliate. 



4. M. arenicola. 



5. M. Michauxii. 



6. M. ochroleuca. 



7. M. glabella. 



8. M. sessilifolia. 

 M. strict a. 



20. M. rigida. 



21. M. Marylandica. 



22. M. obtusa. 



