EVENING-PRIMROSE FAMILY 191 



Plants caulescent; ovary fertile to summit, not prolonged into long sterile portion. 



Capsule nearly or quite sessile. (Subgenus Sphaerostigma; see also O. cardiophylla.) 



Flowers white (yellowish in minor and red in one var. of decorticans) , often drying pinkish; 

 borne in terminal spikes. 



Capsules cylindrical, terete, linear, not thickened in lower portion, scarcely if at all 

 coiled, not noticeably attenuate at tip. 

 Petals 5-7 mm. long, suborbicular; style exceeding corolla, 10-13 mm. long; hypan- 

 thium 4-6 mm. long; capsules refracted or spreading, occasionally coiled. 



17. O. refracta. 



Petals 3 mm. long, spatulate; style shorter than corolla, 3-4 mm. long; hypanthium 

 2.5-3 mm. long; capsules divaricately spreading. 



18. O. chamaenerioides. 

 Capsules not strictly cylindrical, but somewhat enlarged near base and attenuate at tip. 



Mature capsules usually distinctly contorted and coiled, not merely bent and curved, 

 quite slender, not subfusiform in shape (see also O. decorticans desertorum). 

 Flowers minute; petals 1-2 mm. long, narrowly obovate; style 1.5 ram. long; 

 hypanthium 1 mm. long; filaments distinctly unequal. 



19. O. minor Cusickii. 



Flowers larger; petals 3.5-5 mm. long, orbicular-ovate; style 6-12 mm. long; 

 hypanthium 3-8 mm. long; filaments subequal. 

 Flowers and leaves arranged in spicate tufts at ends of naked prostrate 

 branches or on short central stalk; capsules 10-12 mm. long, conspic- 

 uously quadrangular. 20. O. nevadensis. 



Flowers and leaves continuous from base of stems, not in terminal tufts; 

 capsules 14-23 mm. long, not conspicuously quadrangular. 



21. O. alyssoides. 



Mature capsules merely curved or bent, not distinctly contorted or coiled, subfusiform 

 in shape. 



Leaves largely near base, glabrate, lance-ovate to oblanceolate ; stems glabrous or 

 glabrate, with epidermis exfoliating promptly; capsule 15-25 mm. long; 

 seeds ash-colored and linear-obovoid. 22. O. decorticans. 



Leaves well-distributed, glandular-pubescent to glandular-villous, ovate to oblong- 

 ovate; stems glandular; epidermis exfoliating tardily if at all; capsule 

 10-15 mm. long; seeds brownish, rhomboid-prismatic. 



23. O. Boothii. 



Flowers yellow, often drying greenish, borne in axils of foliage-leaves. 



Capsules terete, cylindrical or subfusiform, but not quadrangular; leaves narrow, 1-4 mm. 

 wide, usually linear-oblong. 

 Plant with several naked, fine, often capillary stems, each bearing leafy inflorescence 

 at tip; capsule subfusiform, almost straight, 5-8 mm. long. 



24. O. andina. 



Plants with stems leafy from base; capsules terete, straight or coiled, 15-40 mm. long. 



Flowers small; petals 2.5-3.5 mm. long; sepals 1.5-3.5 mm. long. 



25. 0. contorta. 



Flowers larger; petals 5-15 mm. long; sepals 3-12 mm. long. 



26. 0. dentata campestris. 



Capsules quadrangular; leaves 5-20 mm. wide, lanceolate to ovate. 



Flowers small; petals 1.5-7 mm. long. 27. O. tnicrantha. 



Flowers larger; petals 8-22 mm. long. 



Plants of sea bluffs and inland, greenish except in a desert form; cauline leaves 

 lanceolate to lance-ovate, acute, wavy-margined, thin. 



28. O. bistorta. 



Plants of sea beaches, grayish to silvery (except in var. nitida) ; cauline leaves 

 lance-oblong to orbicular-ovate, obtuse, not wavy-margined, thick. 



29. O. cheiranthifolia. 

 Capsules long-pedicelled. (Subgenus Chylismia) 



Seeds oblong and with an incurving wing, making them appear somewhat boat-shaped, cellular- 

 pubescent; small slender plants, villous below, finely glandular-pubescent above with 

 pinkish white axillary flowers 4-5 mm. across. 30. O. pterosperma. 



Seeds obovoid, rounded or angled, not winged; flowers not axillary, but in terminal racemes or 

 panicles. 



Leaves orbicular-cordate, well distributed, not at all pinnatifid. 



31. O. cardiophylla. 



Leaves ovate, oblong or lanceolate, commonly pinnatifid and near base of plant (except in 

 O. kcrnensis). 

 Capsules linear, elongate, usually over 2 cm. long. 



Leaves not in basal rosette, stem-leaves secund; plant 8-12 cm. high. 



32. O. kernensis. 

 Leaves in basal rosette; plant 10-60 cm. tall. 



Stems coarse, commonly branched only at base if at all; pedicels 3-15 mm. 

 long; capsules linear, widely spreading, commonly 5-9 cm. long; an- 

 thers hairy. ii- O. brevipes. 



Stems slender, commonlv branched above; pedicels capillary, 10-25 mm. 

 long; capsules linear, 15-35 mm. long; anthers glabrous. 



34. O. multijuga parvtflora. 



Capsules somewhat clavate, usually less than 2 cm. long. 



Branches in well-developed plants few to several and arising at base of plant 

 only, not capillary; capsules 10-25 mm. long; anthers linear, beset with 

 scattering white hairs; style longer than petals. 

 Stems slender; flowers few, not congested; leaves ovate, subentire; petals 



usually less than 4 mm. long. 35. O. scapotdea seorsa. 



Stems fairly coarse; flowers crowded in close terminal clusters; leaves fre- 

 quently with supplementary pinnules on petioles; petals 4-7 mm. long. 



36. O. clavaefortms. 

 Branches in well-developed plants capillary and arising freely throughout the 



plant; anthers oblong, glabrous; style not longer than petals. 



37. O. heterochroma. 



