Doz Leguminaceae 

RR. Heads 20—40-flowered; standard distinctly striate. W. x 
T. procumbens L. (Large Hop-clover) ; z 
QQ. _ Flowers white or pinkish. 
S. Calyx and its lobes | /3 shorter than the corolla; perennials. 
T. Leaflets 0.6—2.5 cm. long; heads ovate or oblong, many-flowered. 
We T. howellii Wats. 
TT. Leaflets 0.6—1.2 cm. long; heads 5—10-flowered. 
U. Stipules oval. E. 
T. gymnocarpon Nutt. 
UU. Stipules lanceolate. U. 
T. depauperatum Desv. 
TTT. Leaflets 2.57.5 cm. long; heads globose, many-flowered. 
V. Leaflets obtuse, rarely emarginate; erect or ascending, not stoloni- 
ferous; stem not rooting at the joints; flowers pinkish; calyx-teeth about 
equal W. E. T, hybridum L. (Alsike Clover) 
VV. Leaflets obcordate to retuse; prostrate with the tip ascending, 
stoloniferous; stem rooting at the joints; flowers white; calyx-teeth 
very unequal. W. C. E. 
gu repens L. (White Clover) 
VVV._ Leaflets mostly retuse; prostrate; flowers white or pinkish; ca- 
clyx-teeth about equal. U. 
T. breweri Wats. 
SS. Calyx-lobes from almost equaling to exceeding the corolla; annuals. 
W.  Calyx-teeth scarious-margined, ciliate. W. E. 
T. ciliolatum Benth. 
WW. Calyx-teeth not scarious-margined, not ciliate. 
X. Leaflets notched at apex. W. E. 
T. hallij How. 
XX. Leaflets not notched at apex. W. 
T. gracilentum T. & G. 
CC. Heads subtended by an involucre. 
Y. Corolla yellow; standard conspicuously enlarged. W. 
T. flavulum Gr. 
YY. Corolla ochroleucous; standard conspicuously enlarged. W. 
T. furcatum Lindl. 
YYY. Corolla not yellow nor ochroleucous; standard not conspicuously enlarged 
except in 7. depauperatum). 
Z. Involucre membranous at least at base, not deeply lobed, the lobes entire 
or toothed; flowers white or light pink. 
a. Plant glabrous. 
b. Involucre none or entire with entire segments; leaflets 6—12 mm. long; 
standard much enlarged; calyx-teeth not branched. U. : 
T. depauperatum Desv. 
bb. Involucre with 7—10 shallow lobes, the lobes spinulose-dentate; 
leaflets 12—25 mm. long; standard not much enlarged; calyx-teeth 
branched. E, T. cyathiferum Lindl. 
aa.» Plant villous; calyx-teeth scarious-margined. ’ 
c. Involucre merely basal, its lobes laciniately toothed; calyx glabrous. 
We es T. microdon H. & A. 
cc. Involucre nearly enclosing the head, its lobes entire; calyx hairy. 
WE: T. microcephalum Pursh 

