Thlaspi. CRUCIFER.E. 123 



txlla, Benth. & Hook. Gen. i. 91 ; Brew. & Wats. Bot. Calif, i. 48. [By B. L. 

 Robinson.] 



D. Californica, Haev. 1. c. Spreading annual, usually branching from the base, 4 inches 

 to a foot iu height : leaves thickish, ovate or almost orbicular, coarsely and obtusely few- 

 toothed or subeutire ; the radical narrowed below to slender petioles ; the cauline nearly 

 sessile, somewhat cuneate at base : racemes very dense, often branched ; pedicels scarcely a 

 line in length : stellate-tomentose sepals erect in anthesis, acutish, about 3 lines long, 

 much exceeded by the spreading white or purplish petals : fruit notched both above and 

 below ; lobes suborbicular, margined, tomentose at the edge, 3 lines or more in diameter. — 

 Eugelm. in Wisliz. Tour N. Mex. 96; Gray, PI. "Wright, ii. 14. Biscutella Californica, 

 Brew. & Wats. 1. c. — Sandy soil, S. California, Th. Coulter, Parry & Palmer; White 

 Water, San Bernardino Co., Calif., Parish, Jones; Lincoln Co., Nev., Coville & Funston. 

 (Lower Calif., Orciitt.) 



Var. maritiraa, Davidson, in litt. Leaves thicker, distinctly fleshy, more densely 

 cauescent-tomeutose : inflorescence very dense ; pedicels " dark purple." — Biscutella Cali- 

 fornica, var. maritima, Davidson, Erythea, ii. 179. — Sand dunes of coast, Los Angeles Co., 

 Calif., Monica, Lyon ; Redondo, Miss Merritt. 



D. "Wislizeni, Engelm. 1. c. 95. Erect, subsimple or occasionally branching from below 

 and somewhat spreading, 1 to 2 feet high, becoming rather stout : leaves crowded, lanceolate 

 or ovate-lanceolate to linear-oblong, narrowed to a slender and often distinctly petiolate 

 base ; the upper sessile : racemes elongated, loose ; divaricate or ascending pedicels 4 to 8 

 lines in length : petals white : fruit notched below, but more frequently short-beaked above, 

 or if notched very shallowly so. — Gray, PI. Wright, i. 10, ii. 14, & PI. Thurb. 299 ; as 

 Dithyroia, Gray, PI. Lindh. pt. 2, 1.50, & PI. Fendl. 116; Torr. in Marcy, Rep. 280, t. 2; 

 Torr. & Gray, Pacif. R. Rep. ii. 159. Iberis, n. sp., Torr. Ann. Lye. N. Y. ii. 166. Biscutella 

 Wislizeni, Brew. & Wats. Bot. Calif, i. 48; Coulter, Contrib. U.S. Nat. Herb. ii. 21.— Com- 

 mon on sandy hills, Arkansas and Texas to Arizona and S. Utah ; fl. April to August. 

 (Mex., Pringle.) 



12. THLiASPI, L. (®Aav, to crush, iu reference to the pods and seeds, 

 which are strongly flattened as if crushed.) — A genus of moderate size, chiefly 

 of S. EurojDe and Central Asia ; glabrous annuals or perennials with undivided 

 sessile and often amplexicaul leaves. Flowers white or purplish. — Gen. no. 

 530; DC. Prodr. i. 175; Reichenb. Ic. Fl. Germ. ii. t. 5 ; Prantl, I.e. 166. 

 [By B. L. Robinson.] 



* Capsules large, orbicular or nearly so, broadly winged, very strongly obcompressed ; sides 

 nerved but not keeled ; apex deeply notched : introduced annual. 



T. ARVENSE, L. (Penny Cress.) A span to a foot high, decumbent or erect, simple or 

 considerably branched above : leaves obtusely and rather remotely toothed or angled ; the 

 lower spatulate ; the upper oblong, obtuse : flowers small : sepals greenish, a line in length, 

 exceeded by the spatulate white petals. — Spec. ii. 646; Eng. Bot. t. 1659; Pursh, Fl. ii. 

 435 ; Hook. Fl. Bor.-Am. i. 58. — Streets of cities, about dwellings, etc., generally dis- 

 tributed and locally common in the northern and eastern parts of the United States and 

 Canada, most copious, however, in Manitoba and adjacent Minnesota, where it bears the 

 name of " French Weed." (Nat. from Eu.) 



# * Capsules obovate or oblanceolate, not broadly winged, nor so strongly obcompressed, 

 sides more or less distinctly keeled; apex until dehiscence entire or very shallowly 

 notched : indigenous species of the West and Southwest. 



T. alpestre, L. Perennial, quite simple or more commonlj^ branched from the base, 2 to 8 

 inches, rarely a foot or more high : rootstock slender, elongated : leaves small, subentire or 

 finely toothed ; the radical obovate or oval, rounded at the apex, narrowed to slender 

 petioles : the cauline ovate or oblong, 3 to 8 lines long, sessile with somewhat auriculate 

 bases : racemes simple, terminal, rather dense ; pedicels divaricate, in fruit 2 to 4 lines long: 

 sepals purplish, thin-margined : petals white or pale purple, 2^ to 4 lines long : capsule 



