MUSTARD FAMILY 259 



at the inflorescence. Leaves oblong or lanceolate-oblong, shallowly dentate or entire, 3-5 cm. 

 long, the lower petioled, the upper clasping ; pedicels slender, 6-12 mm. long, spreading ; racemes 

 short, corymbose ; petals white, 2 mm. long ; pods broadly ovoid or cordate, 3-4 mm. broad ; 

 valve's papillose, keeled, wingless ; style slender, 1-2 mm. long. 



In waste places and fields; well established in many localities in Washington, Oregon, and California. 

 Native of Europe. April-July. 



Lepidium repens (Schrenck) Boiss. Fl. Orien. 1: 356. 1867. Pods lens-shaped, not at all cordate at base, 

 otherwise closely resembling Lepidium Draba L. Fields and waste places, Sacramento Valley, California. 



2. Lepidium Jaredii Brandg. Jared's Pepper-grass. Fig. 1972. 



Lepidium Jaredii Brandg. Zoe 4: 398. 1894. 



Annual, with slender, erect, glaucous, pubescent stems, usually branching from the base, 

 1-2 dm. high. Leaves narrowly lanceolate, entire or somewhat toothed ; flowers in rather loose 

 racemes ; pedicels filiform, 10 mm. long ; petals yellow, 2 mm. long ; pods orbicular, not emargi- 

 nate ; style evident. 



Dry hillsides, Upper Sonoran Zone; southern Inner Coast Ranges and San Joaquin Valley, California. 

 Type locality: near Goodwin, San Luis Obispo County, California. March-April. 



3. Lepidium flavum Torr. Yellow Pepper-grass. Fig. 1973. 



Lepidium flavum Torr. Pacif. R. Rep. 4: 67. 1856. 

 Sprengeria flava Greene, Leaflets Bot. Obs. 1: 198. 1905. 

 Sprengeria Watsoniana Greene, Leaflets Bot. Obs. 1 : 199. 1905. 

 Sprengeria minuscula Greene, loc. cit. 



Glabrous prostrate annual, the stems branched from the base, 1-4 dm. long, brittle at the 



joints. Basal leaves rosulate, lanceolate or oblong-lanceolate, slightly fleshy, pinnatifid with 



short rounded lobes and narrow sinuses ; the stem leaves toothed ; inflorescence often corym- 



bosely branched ; racemes dense, subcapitate ; petals bright yellow ; pod broadly elliptical, 3 mm. 



long, inconspicuously winged, glabrous, finely reticulate, bifid at the apex, the teeth acute, the 



sinus open. 



Sandy bottoms of washes or winter pools, Lower Sonoran Zone; desert regions, from Inyo County, Cali- 

 fornia, to western Nevada, south to Lower California. Type locality: Mojave River, California. March-June. 



4. Lepidium perfoliatum L. Round-leaved Pepper-grass. Fig. 1974. 



Lepidium perfoliatum L. Sp. PI. 643. 1753. 



Annual or biennial, glabrous and glaucous, the stems diffusely branched, 2-6 dm. high. Basal 

 leaves 2-pinnatifid, with linear segments ; upper stem leaves round-ovate, cordate-clasping, en- 

 tire ; pedicels spreading ; petals yellow, 1 mm. long ; pods rhombic-orbicular, about 4 mm. long, 

 minutely notched. 



In waste places, sparingly introduced in the Pacific States, but becoming well established in some localities, 

 especially eastern Oregon and southern California. March-May. 



5. Lepidium campestre (L.) R. Br. English Pepper-grass or Field Cress. 



Fig. 1975. 



Thlaspi campestre L. Sp. PI. 646. 1753. 



Lepidium campestre R. Br. in Ait. f. Hort. Kew. 4: 88. 1812. 



Annual or biennial, hoary-pubescent with scale-like hairs, the stems erect, 2-5 dm. high, 

 leafy up to the inflorescence. Basal leaves 5-7 cm. long, oblong or spatulate-oblong, entire or 

 pinnatifid, long-petioled ; stem leaves entire or slightly dentate, auriculate-clasping ; racemes 

 elongated and dense ; pedicels spreading, 4-8 mm. long ; petals white or yellowish ; pods ovate, 

 5 mm. long, broadly winged at the apex, rough, narrowly notched ; style minute. 



In fields and waste places, naturalized from Europe; infrequent in the Pacific States, but becoming well 

 established in some localities, especially in eastern Oregon and Lake Tahoe region, California. May— July. 



6. Lepidium montanum Nutt. Mountain Pepper-grass. Fig. 1976. 



Lepidium montanum Nutt. in Torr. & Gray, Fl. N. Amer. 1: 116. 1838. 



Perennial, more or less puberulent or hirsutulous, the stems often several from the same 

 root, 2-4 dm. high. Basal leaves 2-pinnatifid with oblong or obovate segments, the upper pin- 

 natifid or lobed, rarely entire ; racemes dense ; pedicels 5-6 mm. long ; petals 2 mm. long, clawed ; 

 pod broadly ovate, 2 mm. long, narrowly winged, obscurely notched at the apex ; style scarcely 

 1 mm. long. 



Mountain valleys and plains, Arid Transition Zone; eastern Oregon to Wyoming, south, east of the Sierra 

 Nevada, to Mono County, California, Nevada, Arizona, and New Mexico, also northern Mexico. Type locality: 

 "Plains of the Rocky Mountains on western side, to the borders of the Oregon." April-June. 



Hitchcock (Madrono 3: 304. 1936) refers our plants to variety L. montanum var. canescens (Thell.) 

 C. L. Hitchcock. 



7. Lepidium Jonesii Rydb. Jones' Pepper-grass. Fig. 1977. 



Lepidium Jonesii Rydb. Bull. Torrey Dub 29: 233. 1902. 



Lepidium alyssoides var. Jonesii Thell. Denks. Schweiz. Gesell. Naturwiss. 41, abh. 1: 208. 1906. 



Lepidium montanum var. Jonesii C. L. Hitchcock, Madrono 3: 309. 1936. 



Perennial, glabrous or minutely puberulent, the stems usually several, erect, corymbosely 

 branched above, leafy. Lower leaves pinnatifid with oblong-acute segments; upper leaves 1.5-50 



