356 BRASSICACEAE 



43. D. oxyloba Greene. Cespitose perennial; stems 2-5 dm. high, leafy; 

 basal leaves 2— i cm. long, oblanceolate, remotely dentate or entire, finely ap- 

 pressed-stellate; stem -leaves ovate or lanceolate; petals golden yellow, 4r-5 mm. 

 long; pedicels ascending-spreading, about 8 mm. long; pods 8-10 mm. long, 

 2 mm. wide, finely pubescent. Mountains: Colo. Submont. — Mont. Jl. 



44. D. Helleriana Greene. Cespitose perennial; stems 2-4: dm. high, hir- 

 sute, with branched hairs; basal leaves spatulate or oblanceolate, 2-3 cm. long, 

 loosely stellate; stem-leaves oblong or lanceolate; petals golden yellow, 6 mm. 

 long; pedicels about 1 cm. long, ascending; pod nearly 1 cm. long. D. aurea 

 stylosa A. Gray. Caiions in the mountains: N.M. — Colo. — Utah. Submont. — 

 Moht. My-Jl. 



45. D. luteola Greene. Cespitose perennial; stem 1.5-4 dm. high, cinerous- 

 stellate; basal leaves oblanceolate, usually entire, 2-5 cm. long; stem-leaves 

 entire or dentate; petals 5-6 mm. long, light yellow; pedicels ascending, 7-8 

 mm. long; pod erect, 10-18 mm. long, 3 mm. wide, stellate. Moimtains: 

 Colo. — Utah. Mont. — Alp. Jl. 



46. D. surculifera A. Nels. Cespitose perennial; stems 2-4 dm. high, 

 stellate and villous; basal leaves 3-5 cm. long, oblanceolate, finely and rather 

 sparingly stellate; petals 5 mm. long, golden yellow; pedicels 3-4 mm. long; 

 pod lanceolate, 8-12 mm. long, finely stellate, straight or somewhat twisted. 

 Mountains: Wyo.^ — S.D. Submoyit. — Mont. Jl-Au. 



47. D. aureiformis Rydb. A slender, cespitose, grayish stellate plant; 

 stem strict, 2-4 dm. high; basal leaves spatulate, 2-3 cm. long, acute, entire; 

 stem-leaves closely sessile, oblong-lanceolate; pedicels ascending; pod erect, 

 linear to oblong-lanceolate, 10-15 mm. long, about 3 mm. wide, slightly if at all 

 twisted, stellate. D. Bakeri Greene. Moimtains: Utah — -Colo. — -S.D. Mont. 

 — Alp. Je-Au. 



48. D. aurea Vahl. Cespitose perennial; stem 1^ dm. high; basal leaves 

 oblanceolate, 1-2 cm. long, thick, densely stellate; petals yellow, 4-6 mm. long; 

 pedicels in fruit about 5 mm. long; pods lanceolate, 10-12 mm. long, 2-3 mm. 

 wide, often twisted, pubescent. D. uber A. Nels. Mountains and arctic regions: 

 Greenl. — Lab. — Colo. — Ariz. — B.C.; Eu. Alp. — Mont. 



49. D. decumbens Rydb. Perennial with a short cespitose caudex; stems 

 decumbent, 1-2 dm. high, sparingly pubescent, few-leaved; basal leaves nmner- 

 ous, broadly spatulate, entire, 2-4 cm. long, finely grayish stellate, rather thick; 

 stem-leaves ovate to ovate-lanceolate, sessile, entire; petals pale yellow, about 

 4 mm. long; pedicels very short; pod oblong, 8-15 mm. long, densely pubescent. 

 Summits: Colo. Alp. Au. 



50. D. brachystylis Rydb. Perennial; stems several, decumbent or ascend- 

 ing, with divergent branches, 1-1.5 dm. high, hirsute; basal leaves oblanceolate 

 or spatulate, 1.5-2 cm. long; stem-leaves few, oblong or lanceolate, sessile; pedi- 

 cels short; pod oblong, finely stellate, 8-12 mm. long, ascending; style almost 

 obsolete. Mountains: Utah. Subalp. Jl. 



40. ARABIS L. Rock Cress, Wild Candytuft. 



Annual or perennial herbs, glabrous, or pubescent with branched hairs. 

 Leaves alternate, in ours mostly toothed. Flowers perfect, in terminal or axil- 

 lary racemes. Sepals equu.1 or nearly so, sometimes saccate at the base. Petals 

 white, rarely yellowish, pink, or purple, mostly clawed. Stamens 6; filaments 

 free, unappendaged. Pods sessile, elongate, flat, the valves sometimes nerved, 

 not elastically dehiscent; stigma capitate or 2-lobed. Seeds in 1-2 rows in each 

 cell, marginless, margined, or winged. Cotyledons accumbent or nearly so. 



Basal leaves lyrately lobed; perennials. I. Lyratae. 



Basal leaves entire-margined or toothed. 

 Pods erect or nearly so. 

 Leaves coarsely hirsute. 



Stem-leaves neither cordate nor auricled at the base. II. Furcatae. 

 Stem-leaves cordate or auricled at the base; biennials. 



III. Hirsutae. 



