EVENING PRIMROSE FAMILY 587 



g. Plants with the leaves and flowers home at the ground in a iasal tuft or rosette on the root- 

 crown; flower-huds erect; seeds in two rows in each cell; perennials; deserts and 

 east side of the Sierra Nevada or its easterly crests. 

 Tips of calyx -lobes not free in the bud ; seeds not angled. — Subgenus Pachylophis 



Flowers yellow; leaves deeply and regularly pinnate (the lobes numerous and well-developed) 

 or sometimes sublyrate; capsules not winged, the angles with a small rounded or 



acutish ridge 4. 0. primiveris. 



Flowers white ; capsules with the angles more or less winged or tuberculate. 



Calyx-tube 1 to 2 inches long; capsules long-beaked, with thick entire wings below; 



herbage finely pubescent 5. 0. xylocarpa. 



Calyx-tube 3 to 5^/^ inches long; capsules shortly beaked, the angles with a coarsely- 

 toothed narrow wing or with tubercles ; herbage commonly pilose 



6. 0. caespitosa. 

 Tips of calyx-lobes free in the bud; calyx-tube 2 to 4 inches long; seeds evidently angled; herbage 



glabrous or glabrate. — Subgenus Lavauxia 7, 0. flava. 



B. Stigma capitate or discoid. 



1. Calyx-tube slender or fHiform, ^'2 to 4 inches long, S to 5 times the length of the ovary ; capsules 



sessile or nearly so; seeds in 2 rows in each cell. — Subgenus Taraxia. 

 Perennials ; leaves and flowers borne in a rosette or tuft on the ground ; leaves evidently narrowed 

 to a petiole ; capsule not winged. 



Leaves deeply pinnatifid ; capsule densely pubescent 8. 0. tanacetifolia. 



Leaves entire or with 1 or 2 small lobes or teeth ; capsule glabrous. 



Capsule linear, 2 lines wide, at maturity shrunken about the seeds; seeds with a scurfy 



bran-like surface ; petioles pubescent ; coastal 9. 0. ovata. 



Capsule oblong to ovate, 3 to 4 lines wide, not at all shrunken about the seeds; seeds 



smooth, f avose-pitted ; petioles glabrous; high montane 10. 0. subacaulis. 



Annuals ; leaves and flowers borne in a tuft on the root-crown or short stem or on its very short 

 ( 14 to 2 inches long) branches; leaves linear (1 to 3 lines wide), not narrowed to a 

 petiole ; capsule short, obovoid-quadratish, with 4 thick obliquely truncate Avings. 

 Petals 4 to 5 lines long ; leaves 1 to 4 inches long ; stems very short, commonly unbranched, 



but if branched, the branches slender; cismontane 11. 0. graciliflora. 



Petals 1 to 2 lines long; leaves 1 to ly^ inches long; stems commonly with several very stout 

 horizontal branches ; deserts 12. 0. palmeri. 



2. Calyx-tube obconic or narrotu-funnelform, % to 2 lines long, less than half the length of the 



ovary ; seeds in 1 row in each cell; annuals except no. 14. 

 Capsules sessile or nearly so. 



Stamens with anthers all alike. — Subgenus Sphaerostigma. 

 Flowers yellow, solitary in the axils of the leafy stems. 



Capsules evidently quadrangular ; low, more or less spreading plants ; leaves entire 

 or sinuate-toothed ; capsule contorted, the base of it ascending. 



Petals 2 lines long 13. 0. micrantha. 



Petals 3 to 10^^ lines long. 



Leaves white-pubescent ; perennial 14. 0. cheiranthifoUa. 



Leaves green or greenish; annual Ib.O.Mstorta. 



Capsules terete, or at least not evidently quadrangular ; stem leafy to the top, the 

 leaves of the inflorescence scarcely shorter than those below. 



Petals 3 to 8 lines long 16. 0. dentata. 



Petals 1 to 2 lines long. 



Capsules linear, more or less curved, 8 to 18 lines long; petals IY2 to 2 



lines long 17. 0. contorta. 



Capsules lanceolate, straight, 3 to 6 lines long; petals about 1 line long 



18. 0. andina. 

 Flowers white (rarely yellow), borne in terminal spikes, the spikes commonly nodding 

 in the bud ; stems with the leaves strongly reduced above or inconspicuous. 

 Flowers minute (petals about 1 line long); spikes very loose; capsules terete, 



straight, ascending 19. 0. chamaenerioides. 



Flowers conspicuous (petals 2 to 3 lines long). 



Capsules quadrangular, or subterete, all ascending (or at least the base of 



them) ; spikes densely flowered 20. 0. alyssoides. 



Capsules terete, commonly refracted (at least some of the lowest) ; spikes 



rather loosely flowered 21. 0. refracta. 



Stamens alternate petals with oblong anthers, those opposite petals with smaller globose 



anthers.— Subgenus EuLOBUS 22. 0. leptocarpa. 



Capsules long -pediceled ; flowers in dense terminal spikes, the spikes nodding at tip ; desert spe- 

 cies. — Subgenus Chylisiiia. 



Flowers axillary; seeds oblong, winged 23. 0. pterosperma. 



Flowers in terminal racemes or panicles; seeds obovoid, roumded or angled, not winged. 



