western tansymustard, more...
Annuals; glandular or egland-ular; sparsely to densely pubescent, sometimes glabrous distally, canescent or not, trichomes dendritic. Stems erect, unbranched or branched basally and/or distally, (0.8-)1.3-5.7(-9.2) dm. Basal leaves: petiole 0.5-3.6 cm; blade 1- or 2-pinnate, ovate or oblong to oblanceolate in outline, 1-15 cm, lateral lobes (4-9 pairs), linear or oblanceolate to ovate, margins entire or dentate. Cauline leaves sessile or shortly petiolate; blade smaller distally, distal lobes often narrower, surfaces densely pubescent. Racemes considerably elongated in fruit. Fruiting pedicels usually ascending to divaricate or horizontal, rarely descending (at 20-110º angle), straight or slightly recurved, 4-18 (-23) mm. Flowers: sepals spreading to ascending, yellow, purple, or rose, oblong, 0.8-2.6 mm, pubescent; petals (whitish or yellow), narrowly oblanceolate, 1-3 × 0.3-1 mm; median filaments 1-2.8 mm; anthers 0.2-0.4 mm. Fruits erect to ascending, usually clavate, rarely broadly linear (wider distally), not torulose, 4-13(-17) × 1.2-2.2 mm; valves each with distinct midvein; septum not veined; ovules 16-40 per ovary; style obsolete, 0.02-0.2 mm, glabrous. Seeds biseriate, reddish brown, oblong, 0.6-0.9 × 0.4-0.5 mm.
Plant: Annual forb 10-50 cm Leaves: leaves alternate, pinnate, bipinnate, or pinnatisect, 3-7 cm long Flowers: flowers minute, cream, in elongate racemes Fruit: a 2-celled clavate capsule, 5-10 mm long; Seeds 5-20 per chamber, 2 rows per chamber, 0.5-1 mm Misc: Washes, slopes, often saline soils; < 2500 m. Notes: pedicels spreading/ascending, 4-20mm; fruit dehiscent with membrenaceous septum remaining attached References: J.C. Hickman, ed. The Jepson Manual. W.B. McDougal. Seed plants of Northern Arizona. USDA website.ASU specimens.
Erect, 2-7 dm; lvs oblong to oblanceolate, the lower the larger, bipinnate, or pinnate with deeply pinnatifid segments, the upper progressively reduced and less dissected; fls 2-4 mm wide; mature racemes elongate, to 3 dm, with widely divergent pedicels 5-20 mm; frs narrowly clavate, 5-13 נ1-2 mm; seeds in 2 rows in each locule, at least near the middle; 2n=14, 28, 42. Dry, open or sparsely wooded places; throughout most of N. Amer. Two vars. in our range. Var. pinnata, occurring chiefly on the coastal plain from se. Va. to Tex., has canescent, nonglandular herbage (sometimes glandular in the infl), and spreading or ascending frs 5-10 (avg 1) mm. (Sisymbrium canescens) Var. brachycarpa (Richardson) Fernald, a chiefly northern plant extending s. to N. Engl., W.Va., Tenn., and Tex., has glandular (sometimes also hairy) herbage (incl. the infl) and ascending to erect frs 6-13 (avg 9) mm. (Sophia p.; S. incisa; S. intermedia; S. millefolia)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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