292 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Flowers rose-colored; whole plant roughly 
stellate-pubescent. 
Base of the stems woody and branched. 9. A. perennans. 
Base of the stems herbaceous or 
nearly so, simple........---.----- 10. A. sparsiflora, 
Radical leaves entire or merely denticulate. 
Pods reflexed. 
Pubescence densely and finely stellate, 
whitish; pods 2 mm. wide. ......-.-.- 12. A. puberula. 
Pubescence scant, stellate, or wanting; 
pods 3 to 5 mm. wide. -......----.--- 13. A. suffrutescens. 
Pods not reflexed. 
Pods divaricate; herbage soft pubescent 
with stellate hairs ......-.-...------- 11. A. bolanderi. 
Pods ascending. 
Plant glaucous; lower leaves finely and 
densely stellate-pubescent ........ 14. A latifolia. 
Plant green; pubescence scanty. 
Stems several, slender, from a 
woody caudex; leaves small... 17. A. microphylla. 
Stems solitary or few from a her- 
baceous or scarcely woody base. 
Tall 30 to 60 cm.; plant some- 
what glaucous; pubescence 
of 2-forked hairs. ....-..-- 15. A. drummondit. 
Low 10 to 30 cm.; plant glab- 
rous or somewhat stellate 
pubescent below. .....--- 16. A. lyalliz. 
1. Arabis lyrata occidentalis S. Wats. in Gray, Syn. FI. 11: 159. 1895. 
Type Locauity: ‘From Alaska to British Columbia and the eastern side of the Rocky 
Mts. in Brit. America; Point Pelee on Lake Erie, Macoun.” 
Rance: Alaska to Washington and eastward to Lake Erie. 
SPECIMENS EXAMINED: ‘On Nooksack River near Mount Baker,” Suksdorf 1999. 
ZONAL DISTRIBUTION: Hudsonian. 
2. Arabis whitedii Piper, Bull. Torr. Club 28: 39. 1901. 
Type Looauity: Wenache, Washington. Collected by Whited. 
Rance: Eastern Washington. 
SPECIMENS EXAMINED: Wenache, Whited 1057; Crab and Wilson creeks, Sandberg & 
Leiberg 275. 
ZONAL DISTRIBUTION: Upper Sonoran. 
Mature specimens collected by Whited, May 19, 1905, show the ripe pods to be nearly 
erect, 17 to 20 mm. long, finely and densely stellate-pubescent, and nearly always longer 
than the divergent pedicels with which they form a pronounced angle; seeds wingless, in a 
single row; cotyledons accumbent. It may be a biennial. 
This species is not closely related to any other, in my opinion, but is to be ass@ciated 
perhaps with A. nuttalliz Robinson. 
3. Arabis nuttallii Robinson in Gray, Syn. FI. 11: 160. 1895. 
Arabis spathulata Nutt.; Torr. & Gr. Fl. 1: 81. 1838, not DC. 1821. 
Type Locauity: “Lofty dry hills of the Platte, from the Black Mountains to the central 
chain.” 
Rance: Washington to Montana and Nevada. 
