Tropidocarpum. CRUCIFER^. 141 



B. pilosa, Hook. Fereunial, similar in habit to scapose forms of the preceding species : 

 leaves deusely clustered at the base, liuear-lanceolate, pilose upon both surfaces and margin, 

 chiefly with simple hairs : flowers considerably larger than in the last, fragrant (odor said 

 to resemble that of the lilac). — Fl. Bor.-Am. i. 65, t. 17 ; Torr. & Gray, Fl. i. Ill ; Seem. 

 Bot. Herald, 51. ? jB. rosea, Buuge, Del. Sem. Dorp. 1839 (Liunaja, Lit.-Ber. 1840, 118). — 

 " Sandy shores of the Arctic Sea at the mouth of the Mackenzie River," Dr. Richardson ; 

 coast west of Cape Bathurst, Pidlen, ace. to Seemann. 



B. humilis, Kobinson, n. sp. Pubescent throughout with branched hairs : root single, not 

 strongly thickened : stems several, spreadiug-asceudiug, simple or not infrequently branched, 

 leafy, 2 inches to a span high, terete, slender, wiry : leaves linear-oblong or spatulate, sub- 

 entire to shallowly sinuate-pinnatifid, chiefly basal; the cauline rather small and remote: 

 flowers small, white or purplish ; pods linear, terete, more or less torulose, erect, 5 to 9 lines 

 in length; septum nerveless. — Sisijmbrium humile, C. A. Mey. in Ledeb. Fl. Alt. iii. 137; 

 Fournier, Sisymb. 136; Ledeb. Ic. t. 147. Arabis petraa, Hook. Fl. Bor.-Am. i. 42; Gray, 

 Man. eds. 1-5 ; not Lam.^Ve Wats. Bot. Gaz. xii. 200. — Willoughby Mt., Vermont, Mann, 

 Denne, Grout & Eggleston, &c. ; Anticosti, Pursh, Macoun, to Oregon, and northward to 

 Alaska, Stonei/. (Siberia.) A species in habit, pubescence, and technical characters quite 

 as near Brnija as Sisi/mbriiiw, and possessing the characteristic septum of the former genus. 

 Dr. Watson in an herbarium note has expressed the opinion that the American plant is 

 distinct from the Asiatic, but in what characters does not appear. 



29. TROPIDOCARPUM, Hook. (TpoTrt?, keel, and /capTrds, fruit, from 

 the carinate valves of the capsules.) — A small Californian genus of slender erect 

 simple or sparingly branched more or less hirsute-pubescent annuals, reduci- 

 ble to three species. — Ic. t. 43, 52 ; Benth. & Hook. Gen. i. 82 ; Davidson, 

 Erythea, ii. 179. — The fruit in T. duhium and T. cajipandeum is highly 

 anomalous, even to the suggestion of monstrosity, and merits anatomical and 

 developmental study with more copious material. Aside from the fruit, satis- 

 factory characters for specific distinction are most difficult to define. The leaf- 

 outline, pubescence, length of pedicels, size of flowers, &c., all vary greatly but 

 as it seems independently of each other. [By B. L. Robinson.] 



T. gracile, Hook. Leaves shallowly or deeply pinnatifid ; segments acutish, cleft or entire, 

 very variable in number, form, and size ; the cauline leaves gradually reduced ; the spread- 

 ing pedicels axillary, 3 to 10 lines long: pods lance-linear to linear, strongly obcompressed 

 throughoiit ; style slender ; seeds in 2 rows. — Hook. 1. c. t. 43 ; Torr. & Gray, Fl. i. 94 ; 

 Torr. Pacif. R. Rep. iv. 66; Brew. & Wats. Bot. Calif, i. 44. T . scabriuscuhnn, Hook. Ic. 

 t. 52 ; Torr. & Gray, 1. c, only a roughish form. — Centr. and S. California, chiefly near the 

 coast. The septum of the fruit, not found by Hooker, appears to be regularly present, 

 although very narrow. 



? T. dubium, Davidson, 1. c. Closely similar in habit and foliage to forms of the preced- 

 ing : capsule linear, 2-celled and strongly obcompressed toward the apex, but 1-celled and 

 with valves flattened below ; both parts fertile ; placenta 2. — W. California in vicinity of 

 Los Angeles, Nevin, Davidson ; and Contra Costa Co. at Antioch, Brandegee (collected 

 with T. gracile) ; Byron Springs, Brandegee (collected with T. gracile and T. c.apparidenm). 



? T. capparideum, Greene. Foliage much as in T. gracile; the upper leaves somewhat 

 more deeply parted and with longer subentire segments: fruit lance-oblong, 8 to 11 lines in 

 length, 2 lines in breadth, 1-celled, 6-nerved, 4-valved, tipped with a slender style; placenta 

 commonly 4, and seeds di-stinctly 4-seriate. — Pittonia, i. 217, & Fl. Francis. 278. — Alkaline 

 soil, Centr. California, at Lathrop, Leiimon, and Byron Springs, Greene, Brandegee. The 

 fruit of this noteworthy plant is not only anomalous in the order, but manifests a tendency 

 to vary, being sometimes divided, sometimes assuming contorted forms, and commonly con- 

 taining a small capsule-like structure at the base, as described and figured by Masters, Gard. 

 Chron. New (2d) Ser. xvii. 11, f. 1. However, many apparently fertile specimens have 

 been collected, and the species must be retained at least until the development of the fruit 

 can have more careful study. 



