44^ FLORA. 



g. SISYMBRIUM L. 



Annual or biennial, mostly tall herbs, with simple entire lobed or pinnatifid 

 leaves, and yellow white or rarely pink flowers. Petals generally elongated. 

 Siliques elongated, linear, many-seeded. Valves mostly 3-nerved, dehiscent. 

 Stigma nearly simple, or with 2 short lobes. Seeds in I row in each cell of the 

 pod, marginless. Cotyledons incumbent. [Ancient Greek name of some crucifer.j 

 A genus of about 50 species, of wide distribution. In addition to the following, 

 about 8 others are found in western N. Am. 



Leaves runcinate-pinnatifid. 



Flowers yellow ; pods 1-1.5 crn l n g> appressed. i. 6". officinale. 



Flowers cream-color ; pods 5-10 cm. long, divergent. 2. S. altissimum. 



Leaves oblong or spatulate, dentate ; flowers white or pink. 3. S. humile. 



1. Sisymbrium officinale (L.) Scop. HEDGE MUSTARD. (I. F. f. 1696.) 

 Erect, 3-9 dm. high, with rigid spreading branches. Leaves runcinate-pinnatifid, 

 the lower petioled, the upper nearly sessile ; lobes oblong, ovate or lanceolate, the 

 lower ones often recurved ; pedicels 2 mm. long, erect in fruit ; flowers yellow, 3 

 mm. broad, pods linear, acuminate, glabrous or slightly hairy, closely appressed; 

 valves with a strong prominent midrib. In waste places, common throughout our 

 area, except the extreme north. Nat. from Europe. May-Nov. 



2. Sisymbrium altissimum L. TALL SISYMBRIUM. (I. F. f. 1697.) Erect, 

 6-12 dm. high, freely branching, glabrous or nearly so. Lowest leaves runcinate- 

 pinnatifid, petioled, the lobes often auriculate; upper leaves shorter petioled, deeply 

 pinnatifid, the lobes linear or lanceolate, often with a narrow projection on the 

 lower side near the base ; uppermost leaves often reduced to linear bracts ; flowers 

 yellowish, about 6 mm. broad ; pedicels 6-8 mm. long, spreading or ascending, 

 thickened in fruit ; pods narrowly linear, divergent, I mm. wide ; valves with a 

 prominent midrib. In waste places, Quebec and Ont. to Alberta, D. C. and Mo. 

 Adventive from Europe. Summer. 



3. Sisymbrium humile Meyer. Low OR NORTHERN ROCK-CRESS. (I. F. f. 

 1698.) Perennial, erect, 1-2.5 dm. high, sparingly pubescent, with branched 

 hairs. Leaves spatulate, or oblanceolate, the lower obtuse, 2-5 cm. long, narrowed 

 into a petiole, sharply dentate or rarely entire, the upper smaller, often acute ; 

 flowers white or pink, 3-4 mm. broad; pedicels 4-6 mm. long in fruit; pods nearly 

 terete, narrowly linear, 1-2 cm. long. I mm. wide ; valves finely nerved ; style I 

 mm. long. In rocky places, Anticosti, Willoughby Mountain, Vt., Lake Superior, 

 to Alaska and Oregon. July. 



10. CAKILE Gaertn. 



Annual, glabrous fleshy branching herbs, with purplish flowers. Siliques 

 elongated, sessile, flattened or ridged, indehiscent, 2 -jointed, the joints I -celled and 

 i -seeded. Style none; cotyledons accumbent. [Old Arabic name.] A genus of 

 about 3 species, natives of sea and lake shores of Europe and N. Am. 



i. Cakile edentula (Bigel.) Hook. AMERICAN SEA ROCKET. (I. F. f. 1699.) 

 Bushy-branched from a deep root, the lower branches spreading or ascending, the 

 central ones erect, 3 dm. in height or less. Leaves oblanceolate. or obovate, ob- 

 tuse, sinuate-dentate or lobed, narrowed at the base, the lower 7-13 cm. long ; 

 flowers light purple, 4-6 mm. broad; petals long-clawed, more than twice the length 

 of the sepals ; pod 1-2 cm. long, upper joint slightly longer than the lower, ovoid, 

 flattened, narrowed into a beak above; lower joint obovoid, not flattened. In sands 

 of the seashore, Newf. to Fla., and along the Great Lakes, N. Y. to Minn. Also on 

 the California coast. Summer. 



u. MYAGRUM L. 



An annual glabrous glaucous branching herb, with entire or undulate oblong to 

 lanceolate leaves, the lower petioled, the upper sessile and deeply auricled at the 

 base. Flowers small, yellow, in elongating racemes ; pedicels short, erect-ascend- 

 ing, bractless. Sepals nearly erect. Petals short ; longer stamens somewhat con- 

 nate in pairs. Silicic obcuneate to spatulate. flattened, indehiscent, falsely 3-celled, 

 i -seeded, tipped by the short style. Seed pendulous ; cotyledons incumbent. 

 [Greek, a fly-trap.] A monotypic genus of Europe and Asia. 



