~ Sethe 
Leguminaceae 231 
AA. Leaflets 3 except in occasional abnormal leaves. 
C. Heads not subtended by an involucre. 
D. Heads on terminal peduncles; plants sometimes stemless. 
E. Leaves glabrous. 
F. Calyx-teeth 3 times as long as the tube. F. (T. altissimum.) 
T. douglasij House 
FF. Calyx-teeth scarcely longer than the tube. 
G. Stem quite evident. 
| H. Stem stout; heads globose; leaflets mostly obtuse; flowers |2—20 
mm. long. E. (7. aitonii.) 
T. beckwithii Brew. 
| HH. Stem slender; heads oblong; leaflets mostly acuminate; flowers 
| 8—14 mm. long. (See P.) 
GG. Stemless or nearly so. E. 
T. haydeni Port. 
EE. Leaves pubescent. 
I. Corolla pink or red or purple. 
J. Perennial; calyx-lobes not plumose, shorter than the corolla. 
K. Stems 3—9 dm. high; leaflets 2.5—5 cm. long; flowers purplish- 
red, not reflexed; stipules acuminate. W. C. E. 
Te pratense 1B (Red Clover) 
KK. Stems 1.5—2 dm. high; leaflets 1.2—2.5 cm. long; flowers 
pinkish or light-red, at length reflexed; stipules acute. U. 
T. oreganum How. 
JJ. Annual; calyx-lobes plumose, equaling or exceeding the corolla. 
L. Leaflets 4—12 mm. long; heads ovate; flowers dark-purple. W. 
T. albopurpureum T. & G. 
LL. Leaflets |2—25 mm. long; heads oblong; flowers pinkish. W. E. 
T. arvense L. (Rabbit-foot Clover) 


II. Corolla yellow or white. 
M. Heads ovoid or oblong; flowers at length reflexed. E. (Appar- 
ently 7. harnevyensis. ) 
T. plumosum Doug. 
MM. Heads obovate. W. C. E. 
T. longipes Nutt. 
MMM. | Heads globose. 
N. Calyx-teeth plumose. / 
O. Lobes of the calyx about equal, 3—4 times as long as the calyx- 
tube. W. T. eriocephalum Nutt. 
OO. Lobes of the calyx unequal, one twice as long as the other and 
as the calyx-tube. E. (7. arcuatum cusickit.) 
T. arcuatum Pip. 
NN. Calyx-teeth hairy but not plumose. 
P. Flowers: with pedicels. C. E. (7. longipes latifolium; T. 
hingit.) TT. latifolium GY’. 
PP. Flowers nearly sessile. E. 
T. covillei House 
DD. Heads on axillary peduncles; plants not stemless. 
Q. Flowers yellow. 
R. Heads 3—15-flowered; standard faintly striate. W. C. 
T. dubium Sibth. (Small Hop-clover) 

