~~ —— 
— 
Pe a et ay ay ae 
Moe 
OXYTHECA POLYGONACE 575 
CHORIZANTHE ’ 
gravelly bars along rivers Southern Oregon to California. 
E. vimineum Doug]. Benth. Trans. Linn. Soc. xvii, 416. Leaves 
orbicular to broadly ovate, 3-10 lines broad, the margins often undulate, 
loosely floccose-woolly above, densely white-tomentose beneath, on slender 
petioles about as long as the blade: peduncles usually diffusely and repeat- 
edly branching from near the base, 6-20 inches high: involucres narrow 
and rather prismatic, 1% lines long, the teeth very short: flowers rose- 
color or yellowish, abouta line long, outer segments obovate, the inner 
only half as broad. On dry plains, Brit. Columbia to California east of 
the Cascade Mountains. 
E. Baileyi Watson Proc. Am. Acad. x, 348. Leaves orbicular to 
broadly ovate, 3-6 lines broad, white-tomentose both sides, petioled: pe- 
duncles diffusely branched 6-12 inches high, wholly glabrous: involucres 
narrow, a line or less long, open at the throat, the teeth obtuse: flowers 
pinkish-white, less thana line long. Dry plains eastern Washington to 
Nevada and California. 
2 OXYTHECA Nutt. Pl. Gambl. 169. 
Slender repeatedly dichotomously branched annuals with the 
leaves all in arosulate tuft and small involucrate flowers. Involu- 
cres few-flowered, more or less pedicellate, gampanulate or turbin- 
ate, herbaceous and not reticulated, 3—5-cleft, the erect or spreading 
lobes mostly terminated by straight slender awns. Flowers perfect ; 
calyx 6-parted, colored, enclosing the achene: the more or less ex- 
serted pedicels intermixed with bracts or bractlets. Achene, so far 
as known, ovate-lenticular, the elongated radical accumbent upon 
the rounded cotyledons. 7 
0. dendroidea Nutt. 1. c. Leaves linear-oblanceolate, hirsute, 6-18 
lines long acute: scape-like stem usually 6-12 inches high very slender dif- 
fuse and much branched from near the base, or stouter and less branched: 
bracts unequal, without awns, linear-oblong to linear, or oblong-ovate in 
the stouter iorms, the lower half-inch long or less, the upper much smaller, 
all moreor less united at base: involucres turbinate, 1-3 lines long, un- 
equally 3-4-lobed, rather fleshy, acutely awned, those in the forks on 
slender pedicels 1-4 lines long, the others mi@re nearly sessile flowers light 
rose-color, half a:line long, outer segments obovate, the inner narrower 
= eae On dry hillsides, southeastern Oregon to Wyoming and 
evada. | 
3 CHORIZANTHE R. Br. 
Low dichotomously branched plants with the leaves mostly 
in a rosulate radical tuft, and small flowers in small involucrate 
heads. Involucres tubular or funnelform, sessile, 2—6-angled or 
costate, and 2—6-toothed or cleft, the divisions more or less divari- 
cate and terminating in cusps or rigid, often uncinate, awns. 
Flowers 1-3 in the involucre more or less exserted. Calyx 6-parted 
or 6-cleft. Stamens 3, or 2,inserted on the baseor more or less ad- 
nate to the tube of the calyx, rarely on its throat. Styles linear, 
with capitate stigmas. Achenes triangular beaked. Embryo with 
inflexed or straight radicle. Ours all annuals. 
C. membranacea Benth. Trans. Linn. Soc. xvii, 416, t. 17. Lanosely 
pubescent when young, glabrate in age: stems erect, 6-18 inches high, 
sparingly branched above; radical and-lower cauline leaves linear, obtuse, 
