MUSTARD FAMILY 261 



mm long, oblong-lanceolate, entire or few-lobed, acute; racemes many-flowered; pedicels about 

 5-7 mm. 'long; sepals early deciduous, 1 mm. long, elliptic; petals more persistent, slender- 

 clawed, white, 4 mm. long ; pods elliptic-ovate, 3-4 mm. long, notched and narrowly winged at 



the apex. 



Plains and river valleys, Sonoran Zones; eastern Mojave Desert, California, to Nevada and Utah. Type 

 locality: "St. George, Utah." April-July. 



8. Lepidium Fremontii S. Wats. Fremont's Pepper-grass. Fig. 1978. 



Lepidium Fremontii S. Wats. Bot. King Expl. 30. pi. 4. f. 3, 4. 1871. 

 Nasturtium Fremontii Kuntze, Rev. Gen. PI. 2: 937. 1891. 



Suffrutescent, glabrous and glaucous, the stems woody below forming a low rounded ever- 

 green bush 2-6 dm. high. Leaves 2.5-6 cm. long, narrowly linear, entire or with 1 or 2 pairs of 

 narrow acute lobes or teeth; racemes numerous; pedicels slender, spreading; petals white, 

 3-4 mm. long; pods 5-8 mm. broad, thin and light colored, shallowly obcordate, with broad 

 rounded lobes, usually tapering at base. 



Arid gravelly or rocky slopes, Lower Sonoran Zone; Mojave Desert, California, to Utah, south to northern 

 Lower California and Arizona. Type locality: Mojave River, California. March-June. 



9. Lepidium virginicum L. Wild Pepper-grass. Fig. 1979. 



Lepidium virginicum L. Sp. PI. 645. 1753. 



Annual, the stems erect, usually simple below, branching above, 15-50 cm. high, glabrous 

 or minutely puberulent. Basal leaves obovate, somewhat lyrately pinnatifid ; stem leaves sharply 

 toothed or entire, the uppermost sessile ; racemes glabrous ; pedicels slender, spreading, 4-5 mm. 

 long ; petals about equaling the sepals, sometimes wanting in the later flowers ; pods suborbicular, 

 about 2 mm. broad; cotyledons accumbent. 



Widely distributed through eastern North America. Rare in the Pacific States. Type locality: "In Vir- 

 ginia." May-Nov. 



10. Lepidium Menziesii DC. Menzies' Pepper-grass. Fig. 1980. 



Lepidium Menziesii DC. Syst. 2: 539. 1821. 

 Lepidium occidentale Howell, Erythea 3: 32. 1895. 



Biennial from an elongated taproot, more or less puberulent or pubescent, the stems erect 

 or decumbent, branching above the base. Lower leaves pinnately parted, the segments toothed 

 or entire; upper leaves incisely dentate to entire; pedicels nearly terete, slender, spreading, ex- 

 ceeding the pods; petals present; stamens 2 or 4; pods lenticular, emarginate, about 3 mm. long, 

 glabrous. 



Cliffs along the coast, Boreal Zones; Vancouver Island to the coast of Oregon. Type locality: "In ora 

 occidentali Americae borealis." June-Aug. 



11. Lepidium texanum Buckl. Texas Pepper-grass. Fig. 1981. 



Lepidium texanum Buckl. Proc. Acad. Phila. 1861: 449. 1862. 



Lepidium intermedium A. Gray, Smiths. Contr. 5: IS. 1853. Not A. Rich. 1847. 



Lepidium medium Greene, Erythea 3: 36. 1895. 



Annual, the stems erect, 3-5 dm. high, branched above, glabrous or nearly so. Lower leaves 

 obovate or oblanceolate, coarsely toothed, somewhat pubescent; upper leaves linear, mostly en- 

 tire, glabrous; racemes open in fruit; pedicels 4-6 mm. long; petals white, about 1.5 mm. long; 

 stamens mostly 2 ; pods orbicular, 3 mm. in diameter, narrowly wing-margined ; style obsolete. 



Sandy soil, Sonoran Zones; British Columbia to California, Missouri, Alabama, and Mexico. Type 

 locality: Fort Mason, Texas. May-Oct. 



12. Lepidium idahoense Heller. Idaho Pepper-grass. Fig. 1982. 



Lepidium idahoense Heller, Bull. Torrey Club 26: 312. 1899. 



Annual with erect stems, 20-50 cm. high, corymbosely branching above, sparingly and mi- 

 nutely puberulent. Lower leaves obovate-oblong, laciniately dentate, the upper sessile, entire or 

 nearly so ; racemes glabrous ; pedicels slender, 4 mm. long, spreading ; petals obovate, 2 mm. long ; 

 pods suborbicular, 2 mm. broad, glabrous. 



Open, dry ridges, mainly Transition Zone; Washington and Idaho to southern California. Type locality: 

 "Right bank of Snake River, near Lewiston," Idaho. April-June. 



13. Lepidium densiflorum Schrad. Common Pepper-grass. Fig. 1983. 



Lepidium densiflorum Schrad. Ind. Sem. Hort. Gotting. 4. 1832. 



Annual, the stems erect, simple below, corymbosely branched above, 2-5 dm. high, glabrate 

 or sparsely puberulent. Lower leaves irregularly toothed, the uppermost entire ; racemes gla- 

 brous; pedicels mostly ascending, slender, 3-4 mm. long; petals none or rudimentary and much 

 shorter than the sepals ; pods suborbicular, about 2 mm. broad, glabrous. 



This species has long been recognized as distinct from L. virginicum L., but erroneously referred to L. 

 apetalum Willd. or L. intermedium A. Rich. 



Widely distributed over North America and common in the Pacific States. Adventive in Europe where it 

 was originally described. May-Aug. 



Lepidium densiflorum var. pubecarpum (A. Nels.) Thell. Bull. Herb. Boiss. II. 4: 705. 1904. Annual, 

 with the general habit of L. densiflorum, but usually lower and more branched and more puberulent. Dis- 

 tinguished chiefly by the pubescent pods. Dry plains and ridges, Upper Sonoran and Transition Zones; Rocky 

 Mountain and Great Basin regions, from Montana to Texas and New Mexico, extending westward to eastern 

 Washington and eastern Oregon. 



