Lepidium. CRUCIFERJE. 45 



23. THLASPI, Linn. 



Pod cuneate-oblong or obcordate, laterally compressed, usually emarginate at the 

 apex, few-seeded ; valves acutely carinate or winged. Seeds somewhat turgid, not 

 winged ; cotyledons accuinbent. Style rather long. Low glabrous herbs with 

 simple stems ; lower leaves rosulate, entire or toothed ; the cauline oblong, auricled 

 and clasping ; flow.ers white or pinkish. 



About 25 or 30 species, inhabiting the temperate and colder regions chiefly of the northern 

 hemisphere. But a single species is indigenous to America, common also to the mountains of 

 Europe and Asia. 



1. T. alpestre, Linn. Stems several from a branching perennial rootstock, 1 to 

 15 inches high : radical leaves obovate or elliptical, an inch long including the 

 slender petiole, entire or sparingly toothed ; cauline leaves ovate to oblong, entire, 

 obtuse or acutish : flowers white, 2 or 3 lines long : pods obovate to cuneate-oblong, 

 3 or 4 lines long, emarginate or truncate or rounded at the summit, 4 - 8-seeded, 

 tipped by a style a line long, horizontal on short pedicels. Watson, Bot. King 

 Exp. 31. T. cochleari forme, DC., and T. montamim, Hook. Fl. i. 58 ; Torr. & 

 Gray, Fl. i. 114. T. Fendleri, Gray, PI. Wright, ii. 14. 



Alpine in the Rocky Mountains from New Mexico to British America, in Oregon and in the 

 mountains of Nevada and Arizona. Probably to be found in N. California and perhaps southward 

 in the Sierra Nevada. 



24. LEPIDIUM, Linn. PEPPER-GRASS. 



Pod orbicular or obovate, strongly flattened laterally, emarginately 2-winged at 

 the summit ; valves acutely carinate ; the cells 1-seeded. Seeds not winged ; coty- 

 ledons incumbent (very rarely accumbent). Low herbs ; with pinnatifid or toothed 

 leaves, and small white (in one species yellow) flowers. The petals in many of our 

 species are often wanting, and the stamens only 2 or 4. 



A genus of nearly 100 species, of both temperate zones. Of the 16 North American species a 

 single one is found on tho Atlantic Coast, the rest being limited chiefly to the southwest and 

 to the region west of the Rocky Mountains, and mostly low annuals of peculiar habit. 



* Low annuals : pedicels flattened : petals white, often wanting : stamens 2 to 4 : 



style none. 

 -I- Pod reticulated. 



1. L. latipes, Hook. Hispid with short spreading hairs or the leaves glabrous : 

 stems several, stout, simple, 1 to 3 inches long : leaves exceeding the stems, irregu- 

 larly and coarsely pinnatifid, the segments linear and entire or lobed : racemes short 

 and capitate, in fruit an inch long or less ; pedicels 1 or 2 lines long : sepals very 

 unequal : petals broadly spatulate, ciliate, greenish, 1 to 2 lines long, much exceed- 

 ing the sepals : pod broadly oval, 2 lines broad, sparingly pubescent, strongly reticu- 

 lated, the broad acute wings nearly as long as the pod. Ic. PI. t. 41 ; Torr. fc 

 Gray, Fl. i. 116. 



In saline soils near the coast, from Martinez to San Luis Rey. 



2. L. dictyotum, Gray. Pubescent throughout with short spreading hairs or 

 the leaves glabrous : stems 1 to 3 inches high, ascending, slender, branching : leaves 

 narrowly linear, 1 or 2 inches long, entire or pinnatifid with a few linear lobes : 

 petals but little exceeding the sepals or wanting : stamens 4 : pods rounded, 1|- lines 

 broad, emarginate with two short acute wings, finely reticulated and pubescent, ex- 

 ceeding the thick erect pedicels. Proc. Am. Acad. vii. 329 ; Watson, Bot. King 

 Exp. 30, t. 4. 



Under sage-brush in early spring at Carson City and Steamboat Springs, Nevada, Anderson, 

 Watson, Mann. 



