MUSTARD FAMILY 89 



16. L. dictyotum Gray. Alkali Pepper-grass. Stems few to many or 

 numerous from the base, decumbent, or at length ascending, 1 to 7 inches long; 

 blades of leaves pinnate with ligulate rachis and few remote linear segments, or 

 quite entire; herbage hirsutulose; raceme rather dense with closely ascending flat- 

 tened pedicels; petals little exceeding the sepals or wanting; pods 1% to 2 lines 

 long, elliptic, finely reticulated, pubescent or glabrous, the wings or teeth at the 

 summit shortly ovatish or semi-ovatish, tending to be obtuse at tip, the sinus nar- 

 row, linear. 



Alkaline soils, 200 to 2000 feet : Livermore and San Joaquin valleys to coastal 

 Southern California. Nevada to Oregon, Washington and Idaho. Mar.-Apr. 



Loca. — Byron Sprs., Davy; Livermore, Greene; Four-mile Slough, Whites Bridge road, 

 Jepson 11,577; San Carlos Creek, San Carlos Range, Jepson 2740; Cholame Valley, se. Monterey 

 Co., Jepson 16,174; Smith Mt. near Dinuba, E. P. Kelley; Tulare, Davy 3050, 3068; Famoso, 

 Kern Co., Jepson 11,598, 11,599; Bakersfield, Heller 7594; Lancaster, Davidson; San Bernardino, 

 Parish 794; Temecula plain, Cleveland. Warner Valley, Lake Co., Ore., Manning. A marked 

 form in low wet places on the west side of the lower San Joaquin Valley has few short (1 to 2 

 inches long) stems which are contorted- or recurved-decumbent: Byron Sprs., Davy; Los Banos, 

 Jepson 11,570a. This form in habit is reminiscent of L. latipes. 



Refs. — Lepidium dictyottjm Gray, Proc. Am. Acad. 7:329 (1868), based on Nevada speci- 

 mens, Horace Mann (Steamboat Sprs.), Anderson (sagebrush lands) ; Jepson, Fl. W. Mid. Cal. 

 228 (1901), ed. 2, 193 (1911), Man. 440, fig. 429 (1925). Var. macrocarpxim Thell. Mitteil. Bot. 

 Mus. Ziirich 28:271 (1906), type loc. Livermore, Greene. 



17. L. acutidens Howell. Mule's-ear Pepper-grass. Stem branching at or 

 above the base, the branches comparatively simple, erect, suberect or diffuse, 4 to 

 12 inches high; cauline leaf -blades linear-subulate, mostly entire, the basal leaves 

 1 to 3% inches long, their blades pinnatifid with few remote linear segments; ra- 

 cemes elongated, usually rather dense, the pedicels erect or spreading; petals none 

 or minute ; pods glabrous or slightly pubescent, lightly reticulated, 2 to 2i/2 lines 

 long, the teeth at apex widely divergent, lanceolate and wing-like, half to as long 

 as the elliptic body; sinus triangular; pedicels flattened, somewhat curved in fruit 

 and rather shorter than the pod. 



Alkaline soil : San Diego Co. ; inner South Coast Range valleys ; west side San 

 Joaquin Valley ; Sacramento Valley ; Lassen and Siskiyou Cos. North to Oregon. 

 Feb.-Mar., fr. Apr.-May. 



Locs. — San Diego, K. Brandegee ; Cholame, Jepson 12,030; Dos Palos, Jepson 11,573; Los 

 Banos, Jepson 11,576; Livermore Valley, Davy; Danville, Contra Costa Co., Davy; Montezuma 

 Hills, Jepson 13,371; Vacaville, Jepson 537, 13,364; Colusa jet, K. Brandegee; Dixey Valley, 

 Lassen Co., Baher ^ Nutting. 



Var. comigerum Jepson var. n. Plant diffuse; wings at summit of pod slender, horn-like, 

 curved outward. — (Plantae diffusae; ad apicem siliquae alae graciles, corniculatae, extrorsae.) — 

 Willows, Jepson 13,363 (type). 



Refs. — LEPiDitiM ACTTTiDENS Howell, Fl. Nw. Am. 64 (1897). L. diotyotum var. acutidens 

 Gray Proc. Am. Acad. 12:54 (1876), type loc. Yreka, Greene. L. oxycarpum var. acutidens Jep- 

 son, Man. 441, fig. 431 (1925). L. oreganum Greene, Fl. Fr. 274 (1871). L. acutidens var. micro- 

 carpum Thell. Mitt. Bot. Mus. Univ. Ziirich 28:271 (1906), type loc. San Diego, Jones 3061; 

 pods iy2 lines long. Var. cornigerum Jepson. 



18. L. oxycarpum T. & G. Salt Pepper-grass. Stem very slender, branched 

 from the base, the branches elongated, erect or ascending, 4 to 6 inches long, bearing 

 flowers more than half their length; leaf -blades narrow, linear and subentire, or 

 pinnate with a few acute linear segments; sepals very unequal, caducous, 1/2 line 

 long; petals none; stamens 2; pods roundish, glabrate, finely reticulated, 1^/4 lines 

 long, tipped with 2 very short and acute widely divergent teeth; sinus usually 

 rounded but often triangular; pedicels widely spreading or retrocurved, very 

 slender, flattened, 1 to 11/2 lines long, often longer than the pod. 



Borders of salt marshes or in alkaline soils, 10 to 1400 feet : lower Sacramento 

 Valley; South Coast Ranges from Alameda Co. to southeastern Monterey Co. Mar. 



