VOL. II.] 



MUSTARD FAMILY. 



149 



7. Arabis hirsuta (L.) Scop. Hairy 

 Rock-cress. (Fig. 1777.) 



Turritis hirsuta L,. Sp. PI. 666. 1753. 

 Arabis hirsuta Scop. Fl. Carn. Ed. 2, 2: 30. 1772. 



Stem strictly erect, nearly simple, i-2 high, 

 rough-hairy or nearly glabrous. Basal leaves on 

 margined petioles, obovate or spatulate, obtuse, den- 

 tate or repand, i / -2 / long; stem-leaves sessile, clasp- 

 ing by an auricled base, lanceolate or oblong; pedicels 

 nearly erect, or appressed, 3 // -6 // long in fruit; flowers 

 2 // _3 // i on g ) white or greenish- white; petals more 

 or less longer than the calyx; pods narrowly linear, 

 erect or appressed, i / -2 / long, about */%" wide; 

 seeds i -rowed, or when young obscurely 2-rowed, ob- 

 long or nearly orbicular, narrowly margined; style 

 very short. 



In rocky places, New Brunswick to British Columbia, 

 south to the mountains of Georgia, Arizona and Cali- 

 fornia. Also in Europe and Asia. May-Sept. 



8. Arabis laevigata 

 Smooth Rock-cress. 



Leaves 

 flowers one 



(Muhl.) Poir. 

 (Fig. 1778.) 



Turrilislaevigata'NLuhl. :Willd. Sp. PI. 3:543. 1801. 

 A. laevigata Poir.in Lam.Encycl.Suppl. i: 411. 1810. 



Glaucous, entirely glabrous, i-3 high, nearly 

 simple. Basal leaves petioled, spatulate or ob- 

 ovate, sharply and deeply dentate, 2'-$' long; 

 stem-leaves sessile, lanceolate, or the upper lin- 

 ear, acute, entire or dentate, clasping by an 

 auricled or sagittate base; pedicels ascending or 

 spreading, 4"-5" long in fruit; flowers greenish 

 white, 2 // -3 // high; petals nearly twice the 

 length of the calyx; pods 3 / -4 / long, i" wide, 

 recurved-spreading ; seeds in i row, oblong, 

 broadly winged; style almost none. 



In rocky woods, Quebec to Lake Huron and Min- 

 nesota, south to Georgia and Arkansas. Ascends to 

 5000 ft. in Virginia. April-May. 



Arabis laevigata lacmiata T. & G. Fl. N. A. 1:82. 1838. 

 Stem-leaves deeply and narrowly laciniate- 

 toothed. Kentucky. 



Arabis laevigata Biirkii Porter, Bull. Torr. Club, 17: 15. 1890. 



linear or lanceolate, elongated, entire or sparingly toothed, not auricled at the base- 

 half the size of the type; petals equalling the sepals. Pennsylvania to North Carolina.' 



9. Arabis Canadensis L. Sickle-pod. 

 (Fig. 1779.) 



Arabis Canadensis L. Sp. PI. 665. 1753. 



Stem nearly simple, i-3 high, pubescent below, 

 glabrous above. Basal leaves narrowed into a petiole, 

 blunt but sometimes acutish, dentate or lyrately lobed, 

 3'-7' long; stem-leaves sessile, not clasping, lanceo- 

 late or oblong, narrowed at each end, toothed, or the 

 upper entire, pubescent; pedicels hairy, ascending and 

 2 // -4 // long in flower, spreading or recurved and 4 //r - 

 6" long in fruit; flowers greenish-white, 2 // -3 // long; 

 petals twice as long as the calyx; pods 2 / -3> / long, 

 \Yz ff broad, scythe-shaped, pendulous; seeds in i row 

 in each cell, oblong, wing-margined; style almost none. 



In woods, Ontario to Georgia, west to Minnesota, Arkan- 

 sas and Texas. Ascends to 4200 ft. in North Carolina. 

 June-Aug. 



