Polygonaceae : 133 
N.  Bracts foliaceous, not all ternate but varying from 2—5. E. 
E. latum Small 
NN.  Bracts not foliaceous, ternate. W. C. E. (E. ovalifoliurh purpu- 
reum; E. ovalifolium celsum; E. ovalifolium vinum; E. vinum; E. ortho- 
caulon; E. ochroleucum.) 
E. ovalifolium Nutt. 
MM. Unmbel compound. 
O. 
Tnvolucres in clusters; flowers white or yellow or purple. E. (E. ovali- 
folium proliferum.) 
E. proliferum T. & G. 
OO. Involucres scattered, mostly solitary; flowers white. 
P. Plants erect or ascending. E. (E. dichotomum. ) 
E. niveum Doug. 
PP. Plants decumbent. E. 
E, decumbens Benth. 
AA. Involucre veinless, not angled. 
Q. Annual; bracts not foliaceous, ternate, small, mostly triangular and rigid. 
R. Leaves all basal; involucre and flower about | mm. long. E. 
E. cernuum Nutt. (Nodding Eriogonum) 
RR. Leaves not all basal; involucre and flower |—3 mm. long. 
S. Stem |—3 dm. high, branching from the base. E. 
E. angulosum Benth. 
SS. Stem 3—9 dm. high, simple except the inflorescence. E. 
: E. annuum Nutt. 
QQ. Perennial; bracts foliaceous, not all ternate but varying from 2—8. 
T. Flowers not contracted to a stipe-like base; akene densely villous. 
U. Plant 3—6 dm. high; leaves scattered along the stem, margins not revo- 
lute. E. E. pendulum Wats. 
UU. Plant | dm. or less high (reaching 3 dm. in E. flavum) ; leaves crowded 
on the much-branched woody base. 
V. Leaf margin not revolute. C. E. 
KE. flavum Nutt. 
VV. Leaf margin revolute. 
W. Plant tomentose; leaves oblong to linear; involucres in heads of 1—-5. 
E. E. acaule Nutt. 
WW. Plant canescent; leaves spatulate; involucres solitary. E. 
; E. minimum Small 
TT. Flowers centracted to a stipe-like narrow base; akene glabrous or nearly so. 
X.  Perianth pubescent. 
Y. Lobes of the involucre reflexed. 
Z. Erect, much-branched; leaves often revolute. 
afew lantalo-—Z2)" cit. high; leaves lanceolate or spatulate. E. 
E. sphaerocephalum Dous!. 
aa. Plant 7—13 cm. high; leaves linear. E. (LE. tenue.) 
E. sphaerocephalum tenue Pip. Mi 
ZZ. Prostrate or nearly so, only the flowering stems erect; leaves not 
revolute. 
b. Leaves 4—1I3 mm. long, densely white-tomentose on both sides; 
peduncles 2.5——-7.5 cm. long, naked. E. 
E, caespitosum Nutt. 
bb. Leaves |2—30 mm. long, densely white tomentose below but pu- 
os 
