TETRADYNAMIA— SILIQUOSA. Arabis. 209 



It is said that U. matronalis, originally brought by Europsean set- 

 tlers to the United States of America, loses its scent the second 

 season, and is obliged to be renewed by fresh seeds from Eu- 

 rope. See the remark under Mthusa, v. 2. 65. 



340. ARABIS. Wall-cress, or Rock-cress. 



Linn. Gen. 3A\. Jmss. 238. K. Br. 711. Comp. ed. 4. 108. Br. 

 in Ait. H. Kew. v. 4. 104. DeCand. Syst. v. 2. 213. Lam. t.563. 

 f. 1—3. 



Cal. erect ; leaves ovate-oblong, convei'ging, deciduous ; 

 2 opposite ones rather the largest, somewhat protuberant 

 at the base. PeL obovate-oblong, undivided, a little 

 spreading, tapering at the base into broadish claws, hardly 

 so long as the calyx. Filam. thread-shaped, erect, sim- 

 ple, unconnected, usually with 4 glands at their base ex- 

 ternally. Antk. roundish-heart-shaped, incumbent. Germ. 

 linear, about the length of the stamens. Style very short, 

 or none. Stigma obtuse, simple. Pod linear, compress- 

 ed, crowned with the permanent stigma ; valves almost 

 flat, ribbed, or veiny, slightly undulated from the protu- 

 berance of the seeds, quite as long as the linear mem- 

 branous partition. Seeds in a single row, pendulous, oval 

 or orbicular, compressed, with or without a border ; co- 

 tyledons flat, accumbent. 



Annual or perennial, leafy, upright herbs. Leaves simple ; 

 entire or toothed ; the radical ones numerous, in a rose- 

 like tuft, mostly stalked ; those of the stem alternate, ses- 

 sile, or clasping, and smaller. Pubesce?ice simple or forked. 

 Fl. in corymbose clusters, white, seldom reddish. Pods 

 in very long clusters. Species numerous, chiefly natives 

 of the northern hemisphere. 



1. A. thaliana. Common Wall-cress. 



Leaves hairy, more or less toothed ; radical ones stalked, 

 oblong. Stamens not much shorter than the petals. Stem 

 branched. Pods pointing upwards. 



A. thaliana. Linn. Sp. PI. 929. Wdld.v.o.bZb. Fl. Br.7\2. Engl. 

 Bot. V. 13. ^ 901 . Curt. Lond.fasc. 2. t. 49. Hook. Scot. 199. 



I DeCand. Syst. v. 2. 226. PolUcli v. 2. 243. t. 4. Fl. Dan. 1. 1 106. 

 A.n. 452, a. Hall. Hist.v.\.\97. 

 Pilosella siliquata. Tlml. Hercyn. 84. t. 7.f. D. 

 Turritis vulgaris ramosa. Tourn. List, 224. Raii Syn. 294. Lind. 

 Alsat.SG.t.l. 

 Bursa pastoris, sive Pilosella siliquosa. Bauh. Hist.v, 2. 870./. 

 VOL. III. P 



