MUSTARD FAMILY 



263 



20. Lepidium acutidens (A. Gray) Howell. Sharp-toothed 

 Pepper-grass. Fig. 1990. 



Lepidium dictyotum var. acutidens A. Gray. Proc. Amer. Acad. 12: 54. 1876. 

 Lepidium orcgonum Howell ex Greene, Fl. Fran. 274, in part. 1891. 

 Lepidium acutidens Howell, Fl. N.W. Amer. 1 : 64. 1897. 

 Lepidium oxycarpum var. acutidens Jepson, Man. Fl. PI. Calif. 441. 1925. 



Annual pubescent throughout with short spreading hairs, the stems branching from the 

 base decumbent or ascending, 10-20 cm. long. Leaves linear, tapering at both ends, entire or 

 faintly and remotely denticulate, 2-5 cm. long, about 2 mm. wide; racemes loose, occupying 

 about two-thirds of the branch; pedicels strongly flattened, appressed to the stem to near the 

 middle, then curving outward ; pod sparingly pubescent or glabrous, strongly reticulate, 4 mm. 

 long including the prominent divergent acute teeth, the sinus between the teeth about 1 mm. 

 deep and 2 mm. wide at the apex. 



Saline or alkaline places, Sonoran Zones; eastern Oregon to southern California. Type locality: Yreka, 

 California. March-July. 



11. CORONOPUS Gaertn. Fruct. 2: 293. 1791. 



Diffuse ill-scented annual or biennial herbs, pubescent with simple hairs. Leaves usu- 

 ally pinnatifid. Flowers small, white. Stamens 2 or 4. Style very short. Silicles small, 

 didymous, compressed contrary to the partition, sessile; valves oblong or subglobose, 

 rugose or tuberculate, falling away from the septum at maturity as closed or nearly closed 

 nutlets. Seeds 1 in each cell; cotyledons narrow, incumbent. [The ancient Latin name.] 



About 6 species, of wide distribution in tropical and temperate regions. Type species, Cochlearia 

 Coronopus L. 



1. Coronopus didymus (L.) J. E. Smith. Lesser Wart-cress. Fig. 1991. 



Lepidium didymum L. Mant. 92. 1767. 



Coronopus didymus J. E. Smith, Fl. Brit. 3: 691. 1800. 



Senebiera didyma Pers. Syn. PI. 2: 185. 1807. 



Carara didyma Britt. in Britt. & Brown, 111. Fl. ed. 2. 2: 167. 1913. 



Stems tufted, spreading, sparingly pubescent, S-40 cm. long. Leaves deeply 1-2-pinnatifid, 

 the lower slender-petioled, the upper sessile ; flowers minute, white, racemose ; pedicels slender, 

 2-3 mm. long in fruit ; pod about 2 mm. broad ; valves rugose, separating into ovoid nutlets. 



In waste places, British Columbia to California, and across the continent; introduced from Europe. 

 April-June. 



12. THLASPI [Tourn.] L. Sp. PI. 645. 1753. 



Erect glabrous annual or perennial herbs, with the basal leaves forming a rosette, 

 entire or toothed, the stem leaves auriculate and clasping. Flowers racemose, white or 

 purple. Pods cuneate or orbicular, mostly emarginate, flattened contrary to the partition, 

 crested or winged ; valves dehiscent. Seeds 2 or several in each cell ; cotyledons accum- 

 bent. [Greek, meaning to flatten, from the flat pod.] 



About 25 species, natives of the arctic and temperate zones. Type species, Thlaspi arvense L. 



Annual, introduced; pod suborbicular, broadly winged and deeply notched. 1. T. arvense. 



Perennial; pod cuneate, obscurely winged and shallowly or not at all notched. 2. T. alpestre. 



1973. Lepidium flavum 



1974 

 1974. Lepidium perfoliatum 



1975 

 1975. Lepidium campestre 



