Arabis. CRUCIFER.E. IGl] 



A. riipcstris, Niitt. iu Torr. & Gray, Fl. i. 81. Turritis ovatn, Piirsli, Fl. ii. 438. T. s,„itlnt- 

 laid, Nutt 1. c. 78. — Moutli of tlie St. Lawronce to Vir;,niiia, wcHtward to New .Mexico 

 and the Sierra Nevada; Oregon, and northwar.l to N. Ahu^ka. (Kn., Asia.) Some of the 

 ()re<ron and Ahu-^kan .<5i)ociniens have siirrlitly l)road«r pods anri loMf,'cr seeds, hut are not 

 otiierwise (li.^tinguisliahlc, nor referahle to Asiatic or IOuroj)ean forms. 

 A. Macounii, Watson. Slender hiennial, hranched from tiie ha.<ie, jmhcscent helow witli 

 mostly stellate hairs, glahrous ahove or nearly so: leaves small and narrow, half inch hmg; 

 the lower few-toothed : flowers very small, pale rose-color, 2 lines long : pods very narrow^ 

 1 to U inches long, half line hroad, glabrous, slightly curved, widely spreading ; pedicels 

 very slender, 2 to 4 lines long: seeds wingless. — Proc. Am. Acad. xxvi. 124. — Itevel- 

 stoke, IJrit. Columbia, ./. Macoun ; H, May. 



A. alpina, L. Biennial and perejinial, loosely stellate-])ubescont throughout or the inflo- 

 rescence glabrous : stems erect or decumbent, from a branching subcespito.se rootstock, 

 leafy : radical leaves oblauceolate, A to ,3 inches long, with l)roadly margined petioles ; canline 

 oblong- to ovate-lanceolate and se.ssile with a more or less cordate or auricled b.-isc : j)etals 

 white or lactcoiis, 3 to 4 lines long, twice longer than the yellowish or purjWish sepals: 

 fruiting pedicels 3 to 8 lines long, glabrous, beaked by a short thick style or stigma sessile; 

 valves nearly nerveless, faintly veined ; seeds orbicular, winged. —Spec. ii. 664. — Lower 

 St. Lawrence, Ciaspe', Macoun, to Labrador and Hudson Strait. (Greenland, arctic and 

 alpine regions of Eu., and Asia.) The A. siricta of Pursh's Flora, collected in Laiirador by 

 Colmtisfer, is probalJy this species. 



* * * * Leaves all entire ; cauline not cordate nor auriculate (or very slightlv so) at base : 

 ]iuliescence, when present, finely stellate, sometimes very fine and den.se : perennial. 



A. platysperma, Gray. Glaucous, sometimes wholly glabrous: stems erect or a.scending 

 from a branching rootstock, 2 to 3 inches to a foot high, simple or branched : lower leaves 

 oblauceolate, ab(.ut 1 inch long or less; the upper oblong- to linear-lanceolate, sessile: ])et.ils 

 rose-color or nearly white, 2 to 3 lines long: pods erect or a little spreading, 1 to 2| inches 

 long by U to 2^ lines broad, attenuate to a short stout style; valves distinctly veined, 

 1-uerved toward the ba.se; seeds orbicular, broadly winged. —- Proc. Am. Acad. vi. 519. — 

 San Bernardino Mts., Calif., Parisli Bros., W. G. IVrifjht, and in the Sierra Nevada north- 

 ward to Mt. Hood, Oregon, Howell Bros.; also on E. Humboldt Mts., Nev., Walsoti. 

 § 3. Turritis, Dill (as genus). Winged seeds narrower than the valves and 



somewhat in two rows. * 



* Radical leaves dentate ; cauline more or le.ss cordate or auriculate at base. 

 -(— Pods erect or spreading. 



A.* confinis, Watson. Scarcely glaucous : the lower leaves usually dentate and finely 

 stellale-pnbe.scent or glabrous : pedicels mostly erect or a.scending : pods more or less spread- 

 ing or t rect. ai)Out 3 inches long, a line broad or le.ss, usually more or less attenuate above 

 and beaked; .seeds rather small, numerous, narrowly oblong, winged. — Proc. Am. Acad, 

 xxii. 466. A. I(cvi(j(ita, Hook. Fl. Bor.-.\m. i. 43, not Poir. .1. hrummandil. Gray, JL-in. 

 ed. 5, 69. Turritis glabra, & var., Torr. & Gray, Fl. i. 78, 666. T. stricta, Torr. Fl. N. Y. 

 i. 53, not Grah. ; Gray, Gen. 111. i. 144, t. 59. — From the Lower St. Lawrence along th^ 

 Great Lakes to Lake Winnipeg, Bourwau, and rare southward to Dracnt, on the Merrinmc, 

 Concord, and Brookline, Mass., C. E. Faxon, W. I'eane ; Thimble Islands, Conn., A. L. 

 Wmton; Cayuga Co., New York, Dmlleij ; Elgin and Dixon, Illinois, G. Vasei/.^ 



Var.* brachycarpa, Wats. & Coulter. More slender and le.ss strict : flowering 

 ))pdicels becoming almost horizontal or even reflexed ; fruit short, 1 to 2 inches long, spread- 

 ing; septum thin, almost hyaline; ovules mo.stly abortive. — Wats. & Coulter in Gray, 

 ]\Ian. ed. 6, 67. A. Ihummoudn. var. I,rarl,,/rt,ri,a, Gray, Man. ed. 5, 69. Turritlx hrarh',. 

 carpa. Torr. & Gray, Fl. i. 79 —Canada from Tadouss.Vc, Pickerin<j,to Milk River Ridge, 

 Alberta, Macoun ; also on the south shore of Lake Superior, Fanre/I. In its extreme form 

 very marked, but certainly intergrading with the type. 



■h- -J— Pods reflexed or widely arcuate sjtreading. 

 ' Northwestward to tlie footlulls of the Rocky Mts. of Canada, Macuun. The dcscrijilion of this 



species lia.s been nioililied to e.xcludc the variety. 



