MUSTARD FAMILY 



59 



Herbage densely whitish-pubescent; leaf -segments soft, obtuse; pods somewhat obcompressed 

 but subteretish. — Sect. Eusmelowskia 1. s. calycina. 



Herbage greenish, thinly pubescent; leaf -segments rigid, acute; pods obcompressed, distinctly 

 though not strongly flattened. — Sect. Polyctenium 2. S. fremontii. 



1. S. calycina C. A. Mey. (Fig. 135.) Plants 11/2 to 4i^ inclies high; herbage 

 densely whitish-pubescent; leaves chiefly in a basal tuft, % to II/2 inches long, the 

 blades pinnately divided into linear or oblong segments 2 to 3 lines long; flowers 

 white with rose-color veins, 1 to 2 lines long; 

 pods linear, 3 to 5 lines long. 



Montane, northern Sierra Nevada in south- 

 eastern Shasta Co. East to Colorado, north to 

 Alaska. 



Loc. — Lassen Peak, CJiesnut 4" Drew. 



Eefs. — Smelowskia cai.ycina C.A.Meyer; Ledeb. 

 PI. Alt. 3:170 (1831), type loc. Siberia; Jepson, Man. 

 427 (1925). Rutchinaia calycina Desv. ; Hook. PI. Bor. 

 Am. 1:58, t. 17, fig. B (1830). 



S. OVAI.IS Jones, Proc. Cal. Acad. ser. 2, 5:624 

 (1895), type loc. Mt. Adams, Wash.; pods ovate, trun- 

 catish or subcordate at base, 1 to 2^2 lines long. — 

 Lassen Peak (Syn. Fl. 1^:469). This is, apparently, 

 only a reduced form of S. calycina C. A, Mey. 



2. S. fremontii Wats. Stems erect, tufted 

 on the root-crown, 2 to 5I/2 inches high; herb- 

 age greenish, thinly pubescent; leaves 1 to IV2 

 inches long, the blades divided into linear-sub- 

 ulate segments 3 lines long; flowers white or 

 lemon-yellow; pods linear-oblong, 21^2 to 5 lines 

 long. 



Dried swales or beds of former pools, 4200 

 to 5400 feet : hills and mountain valleys east of 

 the Sierra Nevada crest from Plumas Co. to 

 Modoc Co. North to Oregon. Apr.-June. 



Locs. — Portola, Plumas Co., E. Branclegee ; Amedee, Lassen Co., Loughridge ; Eagle Lake 

 and Madeline plains, Lemmon; Ewing Creek, Modoc Co., E. M. Austin; "West "Valley, "Warner 

 Mts., L. S. Smith 780; Tule Lake, Manning ; Happy Camp, Modoc Co., L. S. Smith 1230. 



Eefs. — Smelowskia fremontu "Wats. Proc. Am. Acad. 11:123 (1876), based on spms. from 

 near Klamath Lake, Fremont, and n. Sierra Nevada, Lemmon. Polyctenium fremontii Greene, 

 Lflts. 2:219 (1912). Braya pectinata Greene, Erythea 3:69 (1895), type loc. Ewing Creek, 

 Modoc Co., E. M. Austin. 



16. ARABIS L. Rock Cress 



Ours erect and often tall annuals or biennials, or caespitose perennials. Flow- 

 ers rose-purple, white or yellowish-white. Sepals greenish or purplish, erect and 

 equal, or the lateral pair slightly saccate at base. Petals obovate or spatulate, with 

 narrow claw and flat blade, commonlj^ much exceeding the sepals. Pod flattened 

 parallel to the partition, the valves more or less 1-nerved. Seeds more or less 

 winged; cotyledons accumbent. — About 120 species, all continents, but mostly 

 north of the equator. (Name from the land Arabia.) 



A. Leaves all pinnately parted. 



Plants decumbent, branching from base, hirsute; annual or biennial; mainland 1. A. virginica. 



Plants erect, slender, branching above, glabrous; annual; insular 2. A. filifolia. 



B. Leaves entire or toothed, or only the basal pinnately parted. 



1. Seeds nearly marginless; basal leaves broad, mostly spatulate to obovate. 

 Pods semi-terete, strictly erect; herbage glaucous, glabrous except at base; biennial. .3. A. glabra. 

 Pods flattened, ascending or divaricate ; herbage not glaucous. 



Fig. 135. Smelowskia calycina 

 C. A. Mey. a, habit, X %; b, leaf, 

 X 2 ; c, fl., X 5 ; d, pod, X 3. 



