MUSTARD FAMILY 61 



1. A. virginica Trel. Virginia Rock-cress. Annual or biennial, nearly glab- 

 rous; stems several from the base, decumbent or ascending, 7 to 15 inches high; 

 leaf-blades deeply and pinnately parted into nearly uniform segments, the seg- 

 ments oblong or linear, few-toothed or entire; flowers small, white; pods linear, 

 spreading, % to 1 inch long, 1 line broad, on pedicels 1 to 2 lines long, beaked by 

 a short pointed style; valves faintly veined or obscurely 1-nerved at base; seeds 

 in 1 row. 



Open places, or low ground, 10 to 200 feet : lower San Joaquin Valley to South- 

 ern California and northern Lower California. East to Texas and Virginia. 

 Apr.-Oct. 



Locs. — Stockton, Davy, San ford 340; Tracy, Michener 4' Bioletti; Inglewood, Los Angeles 

 Co. (Abrains, Fl. Los. Ang. 178) ; San Diego, C. F. Baker 1644. Tiajuana, L. Cal., Orcmtt 1459. 



Eefs. — Arabis virginica Trel.; Branner, Eep. Geol. Surv. Ark. 1888: 165 (1891) • Jepson 

 Fl. W. Mid. Cal. 219 (1901), ed. 2, 186 (1911), Man. 428 (1925). Cardamine virginica h. Sp! 

 PI. 656 (1753), type loc. Virginia. Planodes virginimm. Greene, Lflts. 2:221 (1912). Carda- 

 mine liidoviciana Hook. Jour. Bot. 1:191 (1834), "banks of the Mississippi," Nuttall. A. ludo- 

 viciana Meyer, Ind. Sem. Petrop. 9:60 (1842). 



2. A. filifolia Greene. Island Rock-cress. Delicate annual; stem erect, 

 slender, branching above, 8 to 12 inches high; herbage glabrous, somewhat glau- 

 cous; leaf -blades pinnately divided with filiform lobes, % to 1 inch long; flowers 

 roseate or purple; petals roundish-obovate, narrowed to a claw, 2i/^ to 3 lines long, 

 about twice as long as the sepals; pods ascending or somewhat spreading, almost 

 filiform-linear, acute, 1% to 1% inches long; seeds in 1 row. 



Shadj^ north slopes, perhaps about 500 to 1000 feet : Santa Cruz Island. 



Refs.— Arabis filifolia Greene, Bull. Cal. Acad. 2:390 (1887); Gray, Syn. Fl. r:159 

 (1895) ; Jepson, Man. 428 (1925). Cardamine filifolia Greene, Pitt. 1:30 (1887), type loc. Santa 

 Cruz Isl. Greene. 



3. A. glabra Bemh. Tower Mustard. Stems bluish-green, erect, simple 

 (very rarely branched) , 2 to 4 feet high from a biennial root; herbage glaucous and 

 glabrous but often hispidulous at base; blades of basal leaves broadly spatulate to 

 narrow-obovate, coarsely dentate or merely denticulate, 1^ to 4^2 inches long, 

 soon withering; blades of cauline leaves ovate to lanceolate, entire, clasping by a 

 sagittate base; petals dull white, 2 to 3 lines long, little exceeding the sepals; pods 

 strictly erect or even appressed to the stem, straight, 3 to 4 inches long, ^ to 

 % line wide, on pedicels 3 to 5 lines long; seeds in 2 rows, narrowly winged or 

 wingless. 



Foothills and mountains, 100 to 4700 feet : Coast Ranges, Sierra Nevada, and 

 cismontane Southern California, widely distributed and not rare, but the plants 

 commonly solitary. North to Canada and east to New England; Europe, Asia, 

 Australia. Apr. 



Locs. — Sierra Nevada: Pit River, Modoc Co., M. S. Baker; Big Mdvrs., Plumas Co., T. Bran- 

 degee; Bear Valley, Nevada Co., Jepson 13,389; Glen Alpine, Pendleton 4" Peed 1207; Dorring- 

 ton, Calaveras Co., Jepson 10,184; Pine Ridge, Fresno Co. Coast Ranges: Yreka, Butler 122; 

 summit New River trail, Trinity Co., Jepson 1994; Hupa, Chandler 1337; Blue Lakes, Lake Co., 

 Jepson; St. Helena, Jepson 32c; Mill Valley, Marin Co., H. A. Walker 632; Fish Ranch, Berkeley 

 Hills, Jepson 13,388; Saratoga foothills, Pendleton 720. Southern California: Fort Tejon, Davy 

 2333; Santa Monica Canon, Barter 313; Rubio Canon, San Gabriel Mts., Peirson 390; Saunder 

 Mdw., Mt. San Jacinto, C. V. Meyer 198; Vandeventer, San Jacinto Mts., Jepson 1431. 



Refs.— Arabis glabra Bernh. Syst. Verz. Erf. 195 (1800); Jepson, Fl. W. Mid. Cal. 219 

 (1901), ed. 2, 286 (1911), Man. 428 (1925). Turritis glabra L. Sp. PI. 666 (1753), type Euro- 

 pean. A. perfoliata Gray, Syn. Fl. 1^:160 (1895). 



4. A. hirsuta Scop. Hairy Rock-cress. Biennial; stem erect, simple or 

 strictly branched, 1 to 3 feet high; herbage deep green, rather sparsely hirsute; 

 leaf-blades entire or sparingly dentate, those of the basal oblanceolate to elliptic- 

 oblong, 1 to 3 inches long, narrowed to short winged petioles, those of the cauline 



