CRUCIFERyE. IX. TURRITIS. X. ARABIS. 



161 



rica, in the kingdom of Quito, in the mountain Cotopaxi, at the 

 height of 6600 feet. A'rabis andicola, H. B. et Kth. nov. spec, 

 amer. 5 p. 81. Petals white, linear, blunt. Seeds innumerable, 

 small, brown. 



Hispidish Tower-Mustard. PI. 2 feet. 



4 T. M6i.Lis (Hook. fl. bor. amer. p. 40.) erect ; lower leaves 

 spatulate, sinuately-toothed, upper ones lanceolate, broadly-sa- 

 gittate, quite entire, all as well as the stem and pedicels covered 

 with numerous spreading soft hairs ; siliques linear-elongated, 

 erect. Q, H. Native of North America, on the shores of the 

 Arctic Sea. Flowers white. 



Soft Tower-Mustard. Fl. May, Jul. Clt. 1826. PI. 1 foot. 



5 T. STRICTA (Graham in edinb. phil. journ. July, 1829. p. 7. 

 Hook. 1. c.) erect, smooth ; leaves lanceolate, radical ones 

 stalked, toothed, cauline ones sagittate, half stem-clasping, a little 

 toothed, siliques linear-elongated, erect. 0. H. Native of 

 North America, in prairies of the Rocky Mountains and about 

 Fort Vancouver, on the Columbia. Flowers pure white. 



Straight-podded Tower-Mustard. Fl. Jun. Jul. Clt. 1826. 

 PI. | to 1 foot. 



6 T. PA'TULA (Graham, in edin. phil. journ. July, 1829. p. 7. 

 Hook. 1. c. but not of Ehrh. or Willd.) erect ; leaves lanceolate, 

 radical ones stalked, toothed, cauline ones sagittate, half-stem- 

 clasping, smooth, and a little toothed ; flowers spreading, as well 

 as linear-elongated siliques. Q. H. Native of North America. 

 Flowers rather large, of a beautiful rose-purple colour. 



Var. a, subpubescens ; radical leaves sparingly pubescent. 

 Native from Canada to Lat. 68., and from Hudson's Bay to the 

 Rocky Mountains, and even to Fort Vancouver, on the Columbia. 



Var. j3, incana ; radical leaves hoary with pubescence. Na- 

 tive on the highest summits of the Rocky Mountains. 



Spreading Tower-Mustard. Fl. Ju. July. Clt. 1826. PI. 1 ft. 



7 T. RETROFRA'CTA (Hook. flor. bor. amer. p. 41.) plant 

 erect, hoary-pubescent, or smooth ; leaves lanceolate, radical 

 ones stalked-toothed, cauline ones sagittate, half-stem-clasping, 

 smooth, a little toothed ; flowers drooping ; siliques linear, elon- 

 gated, and are, as well as the pedicels, bent backwards. 0. H. 

 Native of North America, from Hudson's Bay to the Rocky 

 Mountains, and from Canada to Lat. 68., at the Mackenzie 

 River. A'rabis retrofracta, Graham, in edin. phil. journ. July, 

 1829. Flowers white, with a faint purplish tinge.j 



RetrofractedpeAicelled Tower-Mustard. Fl. Ju. July. Clt. 

 1826. PI. 1 foot. 



8 T. DIFFUSA (Hook. fl. bor. amer. p. 41.) plant quite 

 smooth, glaucous ; stems branched, diffuse ; radical leaves spatu- 

 late, almost entire, cauline ones sagittate, hardly toothed ; sili- 

 ques linear, spreading, twice as long as the pedicels. . H. 

 Native of North America on the shores of the Arctic Sea. 

 Flowers small, and probably white. This may prove to be a spe- 

 cies of A'rabis. 



Diffuse Tower-Mustard. PI. diffuse. 



Cult. As the species of this genus are all weedy-like plants, 

 they are only fit for the arrangements in botanical gardens. They 

 only require to be sown in the open border ; or on rock-work, in 

 any kind of soil. 



X. A'RABIS (originally from Arabia, but this name is not 

 very precise, as the species of the genus are found in many parts 

 of the world, in arid, stony, and sandy places, in cold and mild 

 climates). Lin. gen. no. 818. Lam. ill. t. 563. D. C. syst. 2. 

 p. 213. prod. 1. p. 142. 



LIN. SYST. Tetradynamia, Siliquosa. Silique linear, with 

 flat, 1 -nerved valves. Seeds oval, or orbicular, compressed, in 

 1 row in each cell. Cotyledons flat. Herbs annual or perennial, 

 more or less branched. Radical leaves usually stalked, cauline 



VOL. i. PART n. 



ones sessile or clasping the stem, entire or toothed, rarely lobed. 

 Hairs variable, but usually those on the stems are simple, and 

 those on the leaves are either bifid or trifid. Racemes terminal ; 

 pedicels bractless. Flowers white, very rarely red. The genus 

 is called Wall-Cress in English, because the species usually grow 

 in stony places or on walls. 



SECT. I. ALOMA'TIUM (from a, priv. and Xwyua, loma, fringe, 

 in allusion to the seeds being destitute of a wing round their 

 edge, or with a very narrow one). D. C. syst. 2. p. 214. prod. 

 1. p. 142. Seeds not edged, or girded with a very narrow wing. 



1. Obovatipetala. Cauline leaves cordate, clasping the stem. 

 Limb of petals obovate, spreading, distinct from the clan. 



1 A. VE'RNA (R. Br. in hort. kew, ed. 2. vol. 4. p. 105.) 

 cauline leaves cordate, clasping the stem, toothed, scabrous 

 with 3-parted hairs ; pedicels shorter than the calyx ; stigma 

 somewhat emarginate. . H. Native throughout the south 

 of Europe in corn fields and gravelly places. Hesperis verna, 

 Lin. spec. 928. Smith, fl. grasc. 641. A'rabis violacea, Moench. 

 meth. 259. Turritis purpurea, Lam. fl. fr. 2. p. 491. Mor. 

 hist. 2. p. 241. sect. 3. t. 8. f. 5. Petals small, purple, with a 

 white claw. 



Vernal Wall-Cress. Fl. May, June. Clt. 1710. PL | to ft. 



2 A. RO'SEA (D. C. syst. 2. p. 215.) cauline leaves oblong, 

 somewhat cordate and somewhat stem-clasping, scabrous with 

 branched hairs ; pedicels longer than the calyx ; stigma apicu- 

 lated. $ . H. Native of Calabria about Cozenza. Petals 

 rose-purple, oblong, somewhat wedge-shaped, double the length 

 of the calyx. Deless. icon. sel. 2. t. 23. 



Rose-coloured-dowered Wall-Cress. Fl. May, July. PI. 1 ft. 



3 A. VISCO'SA (D. C. syst. 2. p. 216.) leaves distantly-toothed, 

 scabrous with branched hairs ; radical leaves stalked, obovate- 

 oblong, very blunt, cauline ones ovate-cordate, clasping the stem ; 

 pedicels equal in length with the calyx, which is hairy. 34. H. 

 Native of the north of Persia on the Alps. Cardamine viscosa, 

 Gmel. in herb. Pall. A tufted plant, with white flowers. 



Clammy Wall-Cress. Fl. April, May. PL 4 foot. 



4 A. ALPI'NA (Lin. spec, 928.) leaves many-toothed, lanceo- 

 late, acute, villous with branched hairs, radical ones somewhat 

 stalked, cauline ones cordate, clasping the stem ; pedicels longer 

 than the calyx, which is smoothish. I/ . H. Native of Europe 

 on rocks and among stones in calcareous mountains, in sunny 

 situations ; Spain, Lapland, Greenland, Switzerland, Pyrenees, 

 also Madeira and Labrador, &c. Curt. hot. mag. t. 226. A tufted 

 plant, with white flowers. 



Var. ft, Clusiana (Schrank, fl. mon. 2. p. 125.) leaves more 

 sparingly and more bluntly toothed. Clus. hist. 2. p. 125. f. 2. 

 Var. y, nana (Baugm. trans. 2. p. 263.) A dwarfer plant. 

 Alpine Wall-Cress. Fl. March, May. Clt. 1596. PL i ft. 



5 A. A'LBIDA (Stev. in cat. hort. gor. 1812. p. 51.) leaves few- 

 toothed, hoary, or downy with branched hairs ; radical leaves 

 obovate-oblong, cauline ones cordately-saglttate, clasping the 

 stem ; pedicels longer than the calyx. 1 . H. Native of 

 Tauria and Caucasus on rocks. Jacq. fil. eel. 1. p. 105. t. 71. 

 A. Caudisica, Willd. enum. suppl. p. 45. Schrank. hort. mon. 

 t. 24. A. alpina, Pall. ined. Cheiranthus mollis, Horn. hort. 

 hafn. p. 615. Very like A. alpina, but easily distinguished from 

 it by its larger flowers and few-toothed leaves. A tufted plant 

 with white flowers. 



JF7fc-leaved Wall-Cress. Fl. Jan. May. Clt. 1798. PL | ft. 



6 A. UNDULA'TA (Link. enum. hort. berl. 2. p. 161.) stem 

 erect, and is hairy as well as the oblong-toothed waved leaves ; 

 pods spreading; style the breadth of the pod. I/. H. Native 

 of the south of Europe. Like A. albida, but the whole plant is 



Y 



