198 LEAPLBTS. 



I. ATRATUS. Stems erect, simple, 1 to 3 feet high, bearing a 

 simple and short raceme of large dark-purple flowers at summit; 

 herbage glabrous, glaucescent; leaves oblong to linear, sessile : 

 sepals tipped with a somewhat abrupt long acumination : pet- 

 als nearly f inch long, the oblong limb much wider than the 

 narrow claw, of very dark purple, almost blackish : pods not 

 known. 



Along the Canadian Eiver, Indian Territory, M. A. Carleton, 

 June, 1891 ; type in U. S. Herb. 



There is a type inhabiting the deserts of the Great Basin and 

 of southeastern California which has been masquerading for 

 half a century as a £ej>iiftumyvith yellow flowers ; a circumstance 

 which Doctor Torrey himself in publishing the species consid- 

 ered very extraordinary for a Lepidium and he therefore named 

 it L. ftavum, regarding this as the most salient feature of a 

 species, which nevertheless, has other and more significant pecu- 

 liarities. Not only the flowers but also the whole herbage is yellow 

 — at least decidedly yellow-green. Its stout depressed branches 

 are more or less definitely dichotomous, bearing in the forks and 

 at the ends, not the racemes of any Lepidium, but short subum- 

 bellate clusters of flowers and pods commonly broader than 

 high. The lower pedicels of this cluster are leafy-bracted. The 

 pods themselves are surmounted by a stout persistent style of 

 half their own length, while in most lepidia there is no trace of 

 any style at all. 



Here are then, flve points of divergence from each and every 

 section of Lepidium that can be brought into comparison with it ; 

 and the aggregate of all these marks of this annual of western 

 deserts, gives to the type an aspect more like that of certain 

 desert genera of capparids, such as Oxystylis and Wislizenia, 

 than like any genus of cruciferae that can be mentioned. 



Three subspecies of Speengekia are well isolated geographi- 

 cally, and may take names as follows : 



S. FLAVA. The original of L. flavum, Torr., restricted to the 



