é. 
Contributions from the Gray Herbarium 
k. Stems erga or several from the 
base, and —— e central usu- 
ally the larges 
l. Leaves not satiny; | ‘stiffish hairs 
ore or less 
spre: 
m. —— obovate, eeetaiaie or 
te) 
n, Nutlets « avabe: via indi 
inctly m sciadiath, acu- 
_~ margined, 3.5-5.5 
m. long; species of the 
ics pe ey. ins 10. O. celosioides. 
n. pete narrowly onal, ru- 
ose a iculate, 
sealer less eaetals mar- 
gined m. 
long; species of the east- 
ern Rocky Mountains. 
Stem simple or several 
from the caudex; 
lower leaves scagucat 
. O. glomerata. 
Stems simple or with on 
eral distinctly secon 
ary oo we from the 
base; lower leaves ob- : 
lanceolate..........-: 12. O. affinis. 
m. Leaves linear or narrowly ob- 
MenOeNte oho 13. O. Macounit. 
l. Leaves rca above; stiffish hairs 
present on the under surface 
ORES 2a Fs oeee chs 55 14. O. argentea. 
k. Stems 2-many, tufted; leaves —_ 
ly setose-ciliate......... . O. spiculifera. 
ingly 
g. Perennials, tuft e's 
h. Nutlets more or less rugose and somewhat 
muric 
i. Inflorescence congested even in fruit, the 
pedicels very short; calyx- lobes less : 
Sent S mms dongs to ev ce 16. O. sericea. 
i. apie rigs tmodecatoly open in — 
coming 5 mm. 
ree - the ¢ calyx-lobes about 6 mm. long. Bis O. echinoides. 
ee the ae low and blunt, the 
appe i merely wrinkled. .18. O. nubigena. 
Nutlets (cf. rie ec ck rugose, but if tuber- 
culate, some of the tubercles often somewhat 
confluent; t; tufted perennials with payer d 
br peor caudices Y eethed with dead leaf- 
tems 0.5—1 (rarely 2) dm. hi 
J. sare edits ubescent, apparently with only 
ne sort of closely appressed hairs; nutlets 
deieet muriculate, the caicnatione very 
f. Leaves canescent but the pubescence evidently 
of two sorts, astrigose or tomentulose indu- 
ment interspersed wi ith stiffish more or less 
spreadin, 
