WESTERN SPECIES OF ARABIS. 81 



with subsessile trifid hairs, but the hairs of the petiole, and of 

 lower part of stem long, simple, and setaceous, those of the 

 stem deflexed : cauline leaves, oblong, abruptly acute, auricled 

 at base, the lower of them with some simple hairs, the upper 

 glabrous : rachis of the raceme and also the pedicels glabrous : 

 sepals green, beset with a few short hairs ; petals pale purple, 

 surpassing the sepals by less than half their length : pods 3 

 inches long, a line wide, obtusish, nearly straight, on slightly 

 deflexed pedicels ; the valves traversed by a distinct median 

 nerve : seeds in 2 rows, longer than broad but of singularly 

 varying outline, also often winged on but one side, as often 

 on two, the wings always rather narrow. 



Fort Meade, South Dakota, 28 May, 1887, W. H. Forwood, 

 the specimens on U. S. Herb, sheet 317,556. 



The few species concluding this paper seem in no cases 

 referable to any one of the groups above recognized. 



Arabis pendulina. Biennial or perennial, a foot high, 

 with several suberect stems from around a tuft of basal leaves, 

 these an inch long, oblanceolate, the blade glabrous superfi- 

 cially, the margins of it ciliate with short forked hairs, the 

 broad petiole as much ciliate, but with stouter and simple 

 setaceous hairs, those next the base of the stem quite strongly 

 hirsute throughout ; cauline leaves many, short, ovate or 

 ovate-oblong, sessile, auriculate, erect, glabrous or the auricles 

 above bristly-hairy: flowers small, purple : fruiting raceme 

 long and loose; pods ^A to l}i inches long, obtuse, slightly 

 curved, pendulous on the long rather slender pedicels : seeds 

 distinctly biserial, oval, wingless, marginless. 



In woods of the Charleston Mountains, southern Nevada, at 

 7,000 to 8,000 feet, C. A. Purpus, 1898; his n. 6104 as in 

 U. S. Herb. 



Arabis setulosa. Perennial, the somewhat arcuately 

 ascending and rather slender stems less than a foot high from 

 among a few tufts of rosulate basal leaves, these % inch long. 



