Biennials; glandular or eglandular; finely pubescent, often canescent, trichomes dendritic, sometimes mixed with simple ones. Stems erect, unbranched basally or branched proximally and/or distally, 4-12(-15) dm. Basal leaves: petiole 0.5-3.7 cm; blade pinnate, oblanceolate to obovate or ovate in outline, 1-6 cm, lateral lobes (2-5 pairs), oblanceolate to linear or narrowly lanceolate, (7-25 × 2-10 mm), margins usually entire or serrate, rarely incised, (apex obtuse). Cauline leaves sessile or shortly petiolate; blade smaller distally, distal lobes often narrower, surfaces densely pubescent. Racemes considerably elongated in fruit. Fruiting pedicels ascending to divaricate, straight, 6-15 mm. Flowers: sepals spreading or sometimes ascending, greenish to yellowish, oblong, 1-2 mm, densely pubescent, (trichomes dendritic, sometimes mixed with glandular papillae); petals oblanceolate, 1-2 × 0.5-0.7 mm (equaling or shorter than sepals); median filaments 1.4-2 mm; anthers 0.2-0.3 mm. Fruits divaricate to suberect, linear, slightly torulose, 10-20 (-23) × 0.7-1 mm, (acute at both ends); valves each with distinct midvein, (sparsely to densely pubescent); septum not veined; ovules 16-40 per ovary; style 0.1-0.2 mm, glabrous. Seeds uniseriate or biseriate, light brown, oblong, 0.7-1.1 × 0.5-0.6 mm. 2n = 14. Flowering May-Sep(-Oct). Gravelly grounds, sandy areas, disturbed sites, open forests, plateaus, abandoned mine areas, dry streams and washes; 1500-2600 m; Ariz., Nev., N.Mex.; Mexico (Baja California). As circumscribed here, Descurainia obtusa is a relatively uniform, diploid species. It probably was involved as a parent of D. adenophora, which is a hexaploid readily distinguished by characters discussed thereunder.
Plant: Biennial, erect, coarse, whitish; stem generally 1, simple or branched above Leaves: 1-6 cm, 1-pinnately lobed or -compound, canescent; hairs minute, multibranched, rarely glandular; lobes or leaflets 2-5 pairs, linear to oblanceolate, tip generally obtuse INFLORESCENCE: raceme, elongating; bracts generally 0 Flowers: bisexual; sepals 4, free, 2-2.5 mm, ± < petals, sparsely glandular; petals yellowish, free; stamens generally (2,4)6, generally 4 long, 2 short; ovary 1, superior, chambers generally 2, septum membranous, connecting 2 parietal placentas, style 1, stigma simple or 2-lobed Fruit: capsule, 5-15 mm, linear, straight, generally glabrous; both ends tapered abruptly; pedicel ascending to spreading, 12-25 mm, sparsely glandular; Seeds 24-32 per chamber, 1-2 rows per chamber, closely packed, 0.7-1 mm, elliptic, plump, gelatinous when wet; wing 0; embryonic root at back of 1 cotyledon Misc: Gravelly flats, open woods, lake margins; 900-2200 m.; May-Jun Notes: corolla petals clawed and alternating with sepals, pubescence on leaves are stellate hairs. References: Kearney & Peebles; Arizona Flora. ASU Specimans.