72 



CRUCIFERAE 



Fig. 138, Arabis 

 PLATYSPERMA Gray, a, 

 habit, X %; 6, seed, 

 X2. 



Hijrh montane slopes, often a pioneer on {granite sand areas, 7000 to 13,000 feet : 

 inner North Coast Ran}:^o; Si(M"ra Nevada from Siskiyou Co. to Tulare Co.; San 

 Gabriel Mts.; San Bernardino Mts. June. 



Locs. — North Coast Ranges: Mt. Hull, Lake Co. Sierra Nevada: 

 Horse Camp, Mt. Shasta, Jcpson 59b; Medicine Lake, Siskiyou Co., 

 M. S. Baker 484 ; Mt. Bidwell, Jcpson 7887 ; Eagle Peak, Warner Mts., 

 Jcpson 7973; Silver Lake, Lassen Co., Baker ^ Nutting ; Summit sta., 

 Nevada Co., Jtpson ICOa; Truckee River, Placer Co., Sonne 416; Mt. 

 Taliac, Jepson 8137; Echo Ridge, Eldorado Co., Ottley 1170; Silver 

 Lake, Amador Co., Hansen; Silver Valley, Alpine Co., Jepson 10,151; 

 Sonora Pass, A. L. Grant 270; Kaiser Peak, A. L. Grant 1049; Wild- 

 flower Lake, Kearsarge Pass, Jcpson 890; Mt. Silliman, Jepson 726a; 

 Twin Lakes, W. Fry 304; Alta Peak, Hopping 217; Mt. Whitney, Bur- 

 ton 4' Byerson 43. S. Cal.: Ontario Ridge, Pcirson 58; San Bernardino 

 Mts. (PI. World 20:216). 



Var. imparata Jepson var. n. Herbage glabrous; pods larger (3 

 lines broad), less acute tlian in the species.— (Horbae glabrae; siliquae 

 majores (lin. 3 latae) quam in specie minus acutae.) — Lake Solfatara, 

 s/^l "%. Lassen Peak, E. M. Austin in 1896 (type). 



\Jj W Refs. — Arabis platysperma Gray, Proc. Am. Acad. 6:519 (1865), 



type loc. Mt. Dana, 13,227 ft., and above Ebbets Pass, Brewer 1989; 

 Jepson, Man. 432, fig. 420 (1925). A. covillei Greene; Fedde, Rep. 

 Nov. Sp. 5:243 (1908), type loc. Mineral King, Tulare Co., Coville 4' 

 Funston 1492, 1515. A. conferta Greene, I.e., type loc. headwaters 

 Little Kern River, Purpus 5231. A. oligantha Greene, I.e., type loc. 

 Dinkey Creek, Fresno Co., Hall 4' Chandler 354. A. paupercula Greene, 

 Lflts. 2:77 (1910), type loc. Farewell Gap, Tulare Co., Purpus 52291/2, 

 the pods "a line wide." A. liowellii Wats. Proc. Am. Acad. 25:124 

 (1890), type loc. Ashland Butte, s. Ore., T. Howell. The seeds in A. 

 howellii are not in ''2 rows" as implied by Watson (Syn. Fl. 1^:163, 

 sec. 3, and 167). Howell's specimen (the type) is glalarous with the 

 winged petioles of the leaves sparsely ciliate as said by Watson ; it is 

 an excellent match for Mt. Shasta, Pringle, which we consider good A. platysperma and is so 

 labeled at Gray Herb. (det. S. Watson). A. platysperma shows three forms: (a) herbage pu- 

 berulenl; (b) herbage glabrous save the sparsely cUiate petioles; (c) herbage wholly glabrous. 

 Var. IMPARATA Jepson. 



24. A. inamoena Greene. Pigmy Rock-cress. Stems scape-like, arising from 

 the dense basal leaf -rosettes of the branched caudex, 1 to IV2 inches high; leaf- 

 blades narrowly linear-oblanceolate, hispid, 2 to 5 lines long, about i/^ line wide; 

 pods linear, 10 to 14 lines long, 1 to 2 lines wide (similar to no. 18) . 



High montane plateaus, southern Sierra Nevada, 8500 to 11,500 feet : western 

 Inyo Co. and eastern Tulare Co. June, 



Field note. — This is an interesting dwarf, somewhat resembling an alpine Draba. The large 

 pods are sometimes half the height of the plant. The leaves are persistent for 1 to 3 years in 

 dense whorls below the leaf-rosettes of the season. 



Locs. — Coyote Ridge, near South Lake, Inyo Co., ace. Peirson; Rock Creek, Mt. Whitney, 

 Jepson 5059; Volcano Mdws., Tulare Co.; Ramshaw Mdws., Kern Peak, Mary Haskell. 



Var. acutata Jepson var. n. Leaves oblanceolate, loss densely crowded, glabrous or merely 

 cUiate; pods very acute. — (Folia oblanceolata, minus conferta, glabra ciliatave tantummodo; 

 siliquae acutissimae.) — Young's Lake, Tuolumne Co., 9900 feet, F. TV. Pcirson 7610 (type). 



Refs. — Arabis inamoena Greene; Fedde, Rep. Nov. Sp. 5:243 (1908), type loc. Long Mdw., 

 Tulare Co., Palmer 192; Jepson, Man. 432 (1925). Var. acutata Jepson. 



25. A. parishii Wats. Dwarf Rock-cress. Stems slender, simple, erect, 1 to 

 5 inches high, several to many from the densely tufted simple or branched root- 

 crown; herbage finely stellate-pubescent; basal leaves numerous, the blades linear- 

 oblanceolate, entire, 2 to 5 (or 7) lines long, the cauline leaves few (with linear 

 blades), or none; petals rose-color, 3 to 4 lines long, twice as long as the purplish 

 sepals; pods glabrous, 7 to 9 lines long, 1 to 1^/4 lines wide, ascending on pedicels 

 2 to 3 lines long; style filiform, 2 to 2i/^ lines long; valves 1-nerved and veined; 

 seeds in 1 row, elliptical, narrowly winged. 



