82 CRUCIFERiE. Arabis. 



" Forests of the Rocky Mountains,' toAvards the sources of the Oregon. — 

 Stem tall, sparingly clothed on the lower part with forked hairs. Radical 

 leaves not seen ; cauline ones ahout 2-inches long, sessile or clasping. Flow- 

 ers purple ; petals longer than the sepals, linear-oblong." l*^utt. 



12. A. puherula (Nutt. mss.) : " perennial, somewhat ctEspitose, more 

 or less pubescent with dense stellate hairs ; leaves entire, linear-lanceolate, 

 sessile ; siliques Hat, straight, pendulous, the pedicels about twice the length 

 of the sepals ; seeds Avith a slight margin. 



" Forests of the Blue Mountains of Oregon. — Stem about a span high. 

 Flowers not seen. Siliques slightly pubescent, the central nerve obvious." 

 Nutt. 



13. A. inicrophylla (Nutt. mss.) : "smoothish and somewhat coespitose ; 

 leaves linear, rather acute ; cauline ones very few, sessile : stem filiform, 

 very few-flowered ; silique long, flat, spreading. 



" Rocky Mountains : rather rare. — Leaves scarcely half an inch long. 

 Siliques only 2-3, at the summit of the filiform stem, 2i inches long. Flowers 

 small, pale purple. — A smaller and fewer-flowered species than the pre- 

 ceding." Nittt. 



** Seeds with a broad winged margin. 



14. A. l(2vigata (DC.) : erect, whole plant glabrous and glaucous ; radical 

 leaves oblong-obovate, attenuated into a petiole at the base, or somewhat 

 sessile, acutely dentate-serrate ; cauline leaves sessile; the lower ones lanceo- 

 late, sagittate, sparingly toothed ; uppermost linear, entire ; flowers spread- 

 ing ; siliques linear, narrow and elongated, recurved-pendulous. — DC. ! syst. 

 2. p. 237 ; Spreng. syst. 2. p. 892 ; Darlingt. ! fi. Cest. eel. 2. p. 382. A. 

 pendula, Nutt. gen. 2. p. 70, not of Linn. Turritis laevigata, Muhl. ! fl. 

 Lancast. ined. 1. p. 483, ^ in Willd. sp. 3. p. 543 ; Pursh ! fl. 2. p. 438. 



0. laciniata : cauline leaves lanceolate-linear, remotely and laciniately 

 toothed. 



Rocky woods, and along rivers, Canada ! to Virginia ; west to Missouri 

 and Arkansas ! May. — (2) Stem 1-3 feet high. Radical leaves mostly of a 

 purplish color ; cauline ones 2-6 inches long, acutely toothed (the teeth in 

 /?. long and narrow). Sepals greenish-yellow, nearly as long as the narrow 

 Cuneiform erect (white) petals. SUiques 2-3 inches long and less than a 

 line in breadth, pointed Avith the very short style. Funiculi adhering to 

 the septum at the base. — Willdenow erj-oneously states that the siliques are 

 erect, which mistake has led to much confusion respecting our plant. The 

 description of De Candolle was drawn from a dwarf specimen, Avithout fruit, 

 in Pursh's herbarium. — T. laevigata. Hook. fl. Bar. -Am. 1. p. 43, must be a 

 very different plant from the one here descrioed. 



15. A. Canadensis (Linn.): erect; leaves oblong-lanceolate, sessile, at- 

 tenuate at each end, remotely toothed ; pedicels villous, more than twice the 

 length of the calyx ; siliques pendulous, falcate, pointed with the distinct 

 style.— 79 C. prodr. 1. p. 147 ; Ell. sk. 2. p. 148 ; Deless. ic. 2. t. 28. A, 

 falcata, Mich.T. ! /?. 1. p. 31. A. moUis, Raf. ! in Amer. month, mag. 2. p. 

 43. A. lyrsefoHa, Baf. I. c. 



Rocky places, Canada ! to Georgia ! west to Arkansas ! June-July. — 

 Stem 2-3 feet high, simple, glabrous, pubescent below. Leaves 2-4 inches 

 long, nearly glabrous, or pubescent Avith simple hairs, rarely villous ; the 

 lower ones attenuated into a petiole, and sometimes lyrate or runcinate. Ra- 

 cemes elongated. Pedicels spreading, recurved in fruit, sometimes hispid. 

 Sepals yellowish, hispid. Petals white, oblong-linear, tAvice as long as the 

 calyx, nearly erect. Siliques 2-3 inches Irfng, Ih line Avide, ancipital. Funi- 

 culi adhering to the septum, as Avas first noticed by R. BroAvn. (PI. of Oud- 

 ney, &c. p. 11.) 



