MUSTARD FAMILY 81 



the narrow partition, the surface strongly wrinkled or tuberculate ; valves of the 

 pod falling away at maturity from the persistent axis as closed or nearly closed 

 nutlets. Cotyledons incumbent. — Species 12, all continents but mostly subtropic 

 regions. (Greek korono, crow, and pons, foot, because of the shape of the leaves.) 



1. C. didymus Sm. Wart Cress. Stems numerous, freely branching, dif- 

 fuse or prostrate, i/^ to 2 feet long ; leaves i/^ to 1 inch long, pinnately parted into 

 entire or sharply toothed segments; pods small, about 1 line broad, notched both 

 above and below, thus appearing transversely 2-lobed or didymous, each lobe 

 turgid and finely wrinkled. 



South American weed, naturalized near dwellings, 5 to 1200 feet : cismontane. 

 May. 



Locs. — Pasadena and Los Angeles (ace. Davidson & Moxley, Fl. S. Cal. 153) ; San Fran- 

 cisco, Davy; Berkeley, Jepson 12,046; Montezuma Hills, Solano Co., Jepson 13,356; Drytown, 

 Amador Co., Hansen; Healdsburg, Alice King; Dyerville, Humboldt Co., Jepson 16,431; Hydes- 

 ville, Humboldt Co., Tracy 1234 ; Manning Creek, lower Van Duzen River, M. S. Balcer 91. 



Refs.— CORONOPUS DIDYMUS Sm. Fl. Brit. 2:691 (1800) ; Jepson, Fl. W. Mid. Cal. 229 (1901), 

 ed. 2, 193 (1911); Man. 437 (1925). Lepidium didymum L. Mant. 92 (1767), type European. 

 Senebiera didyma Pers. Syn. 2:185 (1807). S. pinnatifida DC. Mem. Soc. Hist. Nat. Paris 

 1:144 (1799). 



C. PROCUMBENS Gilib. Fl. Lithuan. 2:52 (1781); Jepson, Man. 437 (1925). C. niellii All. 

 Fl. Pedem. 1:256 (1785) ; Jepson, Fl. W. Mid. Cal. 229 (1901), ed. 2, 194 (1911). Cochlearia 

 coronopus L. Sp. PI. 648 (1753), type European. Swine-cress. Fruit notched above, obscurely 

 didymous, strongly roughened and cristate-muricate. — Adventive at San Francisco. 



lonopsidium acaule Rchb. Fl. Germ. 7:26, t. 649 (1829). Cochlearia acaulis 

 Desf. Fl. Atlant. 2:69 (1800), type loc. Portugal. Annual, 2 to 21/2 inches high; 

 stem short, rather densely leafy, each axil bearing a long naked one-flowered 

 peduncle ; leaf -blades ovate, entire, 2 lines long, long-petioled ; pods obcompressed, 

 flattened, round-ovate, 2 lines long. — Adventive at Ferndale, Humboldt Co. {J. P. 

 Tracy, B. D. Douglas) ; native of Portugal, 



26. LEPIDIUM L. Pepper-grass 



Low annuals, rarely perennials, with toothed or pinnatifid leaves and very 

 small flowers ( I/2 to 1 or 2 lines long) . Petals white, rarely yellow, sometimes none. 

 Stamens 6, 4 or 2. Pod an orbicular, ovate or broadly oblong silicic, strongly ob- 

 compressed, and commonly notched or lobed at the more or less winged apex; 

 valves acutely carinate, the cells 1-seeded. Style, if present, persistent in fruit. 

 Cotyledons incumbent or accumbent. — About 123 species, widely distributed, 

 chiefly in temperate and subtropic regions. (Greek lepidion, a little scale, in ref- 

 erence to the flattened pods.) 



A. Style distinctly developed and persistent. 

 Eaeemes racemose (that is, not capitate) ; plants erect or nearly so. 

 Pods not winged nor notched at apex. 



Pods flat, dehiscent; leaves linear-lanceolate, merely sessile; flower-glands distinct 



1. L. jaredii. 

 Pods inflated, indehiseent ; leaves ovate to ovate-lanceolate, auriculate-clasping at base ; 



flower with an annular gland 2. L. draba. 



Pods winged and notched at apex. 



Cauline leaves clasping ; herbage pubescent or grayish. 



Pods thick, winged all around ; blades of upper leaves oblong, sagittate-clasping at 



base, denticulate 3. L. campestre. 



Pods thin, minutely winged at apex only; blades of upper leaves cordate-clasping 



at base, entire _- ; 4. L. perfoliatum. 



Cauline leaves not clasping; species of the deserts or arid regions. 



Herbage minutely puberulent or short-hirsute; biennial 5. L. montanum. 



Herbage glabrous; perennial. 



Stems herbaceous; pods oval 6. L. alyssoides. 



Low woody bush ; pods obcordate 7. L. fremontit. 



