Arabis. CRUCIFER^. 163 



A. rupestris, Nutt. in Torr. & Gray, Fl. i. 81. Turritis ovata, Pursh, Fl. ii. 438. T. spathu- 

 lata, Nutt. 1. c. 78. — Mouth of the St. Lawrence to Virginia, westward to New Mexico 

 and the Sierra. Nevada; Oregon, and northward to N.Alaska. (En., Asia.) Some of the 

 Oregon and Alaskan specimens have sliglitly broader pods and longer seeds, but are not 

 otherwise distinguishable, nor referable to Asiatic or European forms. 



A. Macounii, Watson. Slender biennial, branched from tlie base, pubescent below with 

 mostly stellate hairs, glabrous above or nearly so : leaves small and narrow, half inch long ; 

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

 1 to 1^ inches long, half line broad, glabrous, slightly curved, widely spreading ; pedicels 

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

 stoke, Brit. Columbia, J. Macoun ; fl. May. 



A. alpina, L. Biennial and perennial, loosely stellate-pubescent throughout or the inflo- 

 rescence glabrous : stems erect or decumbent, from a branching subcespitose rootstock, 

 leafy : radical leaves oblanceolate, ^ to 3 inches long, with broadly margined petioles ; cauline 

 oblong- to ovate-lanceolate and sessile with a more or less cordate or auricled base : petals 

 white or lacteous, 3 to 4 lines long, twice longer than the yellowish or purplish 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, Gaspe, Macoun, to Labrador and Hudson Strait. (Greenland, arctic and 

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

 Colmaster, is probably this species. 



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

 pubescence, when present, finely stellate, sometimes very fine and dense : perennial. 

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

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

 oblanceolate, about 1 inch long or less; the upper oblong- to linear-lanceolate, sessile: petals 

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

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

 1-nerved toward the base; seeds orbicular, broadly winged. — Proc. Am. Acad. vi. 519. — 

 San Bernardino Mts., Calif., Parish Bros., W. G. Wri</ht, and in the Sierra Nevada north- 

 ward to Mt. Hood, Oregon, Hoicell Bros.; also on E. Humboldt Mts., Nev., Watson. 



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



somewhat in two rows. 



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

 ■i— Pods erect or spreading. 



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

 stellate-pubescent or glabrous : pedicels mostly erect or ascending : pods more or less spread- 

 ing or erect, about 3 inches long, a line broad or less, usually more or less attenuate above 

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

 xxii. 466. A. Icevigata, Hook. Fl. Bor.-Am. i. 43, not Poir. A. Drummondii, Gray, Man. 

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

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

 Great Lakes to Lake Winnipeg, Botrrucan, and rare southward to Dracut, on the Merrimac, 

 Concord, and Brookline, Mass., C. E. Faxon, W. Deane ; Thimble Islands, Conn., ^. Z. 

 Winton ; Cayuga Co., New York, Dudleij ; Elgin and Dixon, Illinois, G. Vasei/.^ 



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

 pedicels becoming almost horizontal or even reflexed : fruit short, 1 to 2 ijiches long, spread- 

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

 Man. ed. 6, 67. A. Drummondii, var. braehi/carpa, Gray, Man. ed. 5, 69. Ttirritis brachi/- 

 carpa, Torr. & Gray, Fl. i. 79. — Canada from Tadoussac, Pickering, to Milk River Ridge, 

 Alljerta, Macoun ; also on the south shore of Lake Superior, Farwell. In its extreme form 

 very marked, but certainly intergrading with the type. 



H— -)— Pods reflexed or widely arcuate-spreading. 



' Northwestward to the foothills of the Rocky Mts. of Canada, Macoun. The dcsciiption of this 

 species has been modified to e.xclude the variety. 



