k 



Studies in tlie Leguminosae, 



Bv Anna Murray Vail 





I. NOTES ON THE GENUS D0UCH0LU8 (RHYNCHOSIA) IN THE UNITED STATES 



DOLICHOLUS Medik. Vorles. Chur. Phys. 2 : 354. 178;. [Bot 



Beob. des Jahres 1783: 211. 1*^84.] 



[RiiVNCHOSrA Lour. Fl. Cochin. 460. 1790.] 

 [Arcvphvllum Ell. Journ. Acad. Phlla. i: 371. 1818.] 

 [CoPiSMA E, Meyer, Com. PI. Afric. Austr. 132. 183 5-1 837.] 



Key to llie Species 



^ ] 



ConsMA. — Twining, usually prostrate and trailing, or rarely 

 more erect, perennial herbs ; leaves 3-folioIatc, the lateral leaflets in- 

 equilateral : flowers in slender axillary racemes or few-flow^ered 

 clusters : calyx marcescent, not at all foliaceous, somewhat bi- 

 labiate, deeply 4-cIcfl: ; teeth subulate, the middle one the longest : 

 corolla exceeding the calyx-teeth. — E. Meyer. 



I 



Racemes very slender, many-flowered, exceeding the leaves ; flowers and legumes re- 

 flexed. I. n. minimus. 

 Racemes a-G-flowcrcd, as lung as or shorter tluui the leaves. 2. D. pai-vifolius. 

 Flowers shorl-pedicelled, solitary, or several together in the axils of the leaves, 



3. D. Tcxensis. 

 Racemes short-pedvnicled, 2-4-floweretl ; bracts persistent. 4. D. Sxvartzii. 



ARCvrirvLLUM. — Slender, upright or elongated perennial, often 

 twining herbs: leaves simple or 3-foliolate ; lateral leaflets in- 

 equilateral : flowers in short-pedunclcd, axillary, few-flowered or, 



crowded clusters, or rarely elongated racemes : calyx 4-partcd 

 nearly to the base, persistent, the foliaceous segments linear or ob- 

 long-lanceolate, acuminate, nearly equal, the upper ones 2 -toothed : 

 corolla not exceeding the calyx-teeth. — 1^11. Journ. Acad. Phila. 

 I : 371. 1818. 



Prostrate or climliiTig pereimial vines. 



Leaves vmifoliolate or \\\ D. ilZ/rZ/rr/zx// rarely the uppennost trifuliolate ; racemes 



axillary. 



Leaves rcniform, cordate at base. 5. D, Americanus. 



Leaves reniform, truncate at base. 6. D, Michauxii, 



*Tht monotypic genus Pikheria, Nutt. Journ. Acad, riiila. 7: 93. 1S34, 

 though difficult to distinguish from Doiichoius by any absolute characters, differs from it 

 greatly in general appearance and habit. 



( lOG ) 



