26 Contributions from the Gray Herbarium 
F encores» of leaves appressed-canes- 
—_ nig ad any of the hairs 
ading 
3; foam ay lanceolate or oblan- 
aoe - inflorescence moderately : 
CONNIE. 55k, Seite a. var. cinerea. 
J. — neatly linear, elongate; inflor- 
PEMA: hoe ck 28b. var. laza. 
g. Stems slabrous leaves — beneath, 
s pubescent MbOVR se Sing cs 39. O. pustulosa. 
f. Nutlets ond lomaens ; Mexic ae ee 30. O. Palmeri. 
ce. Corolla white or yellow, 7-15 mm. long, the tube dis- 
tinctly sath fr rid the calyx or if og = calyx 
and corolla-tube both more than 6 m 
lets rough, or, if smooth, the fruit ovoid-conical, 
wy 
d. Nutlets more or less roughened; leaves spatulate to 
broadly o se iar or obovate; plants often 
low pent densel ted 
e. Fruit depressed, su sbalsbob: the nutlets usually 
rather bes incurved and always more or 
less separated at the edges, the ventral face 
with rap pre avated groove, but the scar some- 
e. Fruit a a the nutlets erect (unless 
partly aborted), touching at the edges, or, if 
not, the v entral face with an excavated 
open groove in the ventral face 
g. Nutlets disks aped, margined all around, ion 
ee eae ee ey 33. O. Paysonit. 
g. Nutlets ce not margined, ull 
from a much branched caudex; 
pe 1.5 é ; inflorescence 
very yellowish pubescent. ..... 34. O. fulvocanescens. 
se, 1.5-3 high; in- os 
flo ce pallid or slightly yellowish. ..35. O. nitida. 
f. Nutlets more i to rugose, sometimes also m 
ri ; — sa often with an om 
g. Paws inordinately ‘bstose-hiepi d; calyx 
divisions linear, in fruit 10-12 mm. long. 
g. Plants not strongly setose-hispid; calyx 
divisions — ovate-lanceo! ate 
h. Calyx-divisions linear, 8-10 
mm, 
. O. horridula. 
linear but always less than 8 
