a oti 

Onagraceae 265 
B. Tips of the calyx-lobes not at all free in the bud; sides of the capsule not 2- 
ribbed; seeds in 2 rows in each cell. W. 
G. purpurea Wats. 
BB. Tips of the calyx-lobes slightly free in the bud; capsule 2-ribbed at least on 
the alternate sides; seeds in one row in each cell. 
C. Flowers in a short simple spike. W. (G. arnottii: GC. decumbens. ) 
G. lepida Lindl. 
CC. Flowers in numerous short lateral spikeletes. W. 
G. albescens Lindl. 
AA. Flowers in a loose spike or a raceme, nodding in the bud; capsule linear; seeds 
in | row; leaves distant. 
D. Capsule sessile ; calyx-tips mostly free. 
E. Petals 6—12 mm. long. 
F. Ovary and capsule villous: capsule 2-ribbed at the alternate sides. W. E. 
G. quadrivulnera Spach 
FF. Ovary and capsule puberulent: capsule nearly flat at the sides. U. 
G. tenella Spach 
EE. Petals 18—30 mm. long. W. C. 
G. viminea Spach 
DD. Capsules with pedicels; calyx-tips mostly not free. 
G. Petals 6—12 mm. long: pedicel of capsule |—4 mm. long. W.E. 
G. epilobioides Wats. 
GG. Petals 12—30 mm. long; pedicel of capsule 4—15 mm. long. 
H. Plant minutely puberulent; stem somewhat branched above. 
I. Anthers sparingly hairy, large, the terminal part sterile and often hooked. 
W. G. caurina Abrams 
II. Anthers glabrous, small, fertile to the tps. Wo. Ce Er 
G. amoena Lilja (Herald-of-summer) 
HH. Plant hispid with short spreading hairs; stem simple. W. 
G. hispidula Wats. 
ONAGRA EVENING PRIMROSE 
Annual or biennial; stems 315 dm. high (ours), coarse. Leaves alternate. 
Flowers yellow, changing to pink in age, nocturnal, erect before opening. Calyx-tube more 
or less prolonged above the ovary, deciduous; calyx-segments 4, reflexed. Petals 4, equal, 
sessile, obcordate to obovate. Stamens 8, equal; anthers versatile. Stigma deeply 4- 
cleft. Seeds in 2 or rarely more rows, prismatic-angled. (Said to be from Gk. onagros—= 
the wild ass, whose ears the leaves resemble. ) 
A. Petals |—2 cm. long; calyx-lobes shorter than the calyx-tube. W.E. (Oecnothera 
biennis strigosa. ) A. strigosa Rydb. 
AA. Petals 2.5—4 cm. long. 
B. Calyx-lobes nearly glabrous, shorter than the calyx-tube; annual, erect. E. 
A. macbrideae Nels. 
BB. Calyx-lobes densely hairy, as long as or longer than the calyx-tube; biennial. 
Flowers yellow or purplish, drying lighter; stems erect. W. E. (O. muricata 
and Oenothera biennis muricata for our region.) 
A. hookeri Small 
CC. Flowers yellow, drying darker; stems spreading. E. 
A, ornata: Nels. 
