Descurainia paradisa
Great Basin tansy mustard, Nevada tansymustard, paradise tansymustard
erect, branched basally and distally, (often purplish), (1–)1.5–3.2(–4.1) dm.
(soon withered);
petiole 0.3–1.3 cm;
blade pinnate, oblanceolate to obovate in outline, 1.5–3 cm, lateral lobes oblong to linear or lanceolate, (1–5 × 0.3–1 mm), margins entire or dentate.
sessile;
blade smaller distally, distal lobes often narrower, surfaces moderately to densely pubescent.
considerably elongated in fruit.
sepals spreading to ascending, pale yellow, oblong, 0.8–1.2 mm, pubescent;
petals oblanceolate, 0.9–1.3 × 0.2–0.5 mm;
median filaments 0.8–1.2 mm;
anthers 0.1–0.2 mm.
divaricate to ascending, straight, 2.5–7(–9) mm.
divaricate to erect, usually obovoid to clavate, rarely broadly ellipsoid, not torulose, 2–5 × 1–2 mm, (acute basally, obtuse apically);
valves each with obscure midvein;
septum not veined;
ovules 4–10 per ovary;
style 0.05–0.3 mm, glabrous.
uniseriate or biseriate, brown, oblong, 0.8–1.2 × 0.5–0.6 mm.
Descurainia paradisa
Although L. E. Detling (1939) reduced Descurainia paradisa to a subspecies of D. pinnata, molecular data (B. E. Goodson 2007) clearly show that it should not be included in that species. The boundaries of D. paradisa in its northern and southern ranges tend to be blurred relative to D. nelsonii and D. pinnata, respectively.
R. C. Rollins (1993) and N. H. Holmgren (2005b) recognized some of the Nevada plants of Descurainia paradisa that have eglandular racemes as a subspecies and variety (nevadensis), respectively. This poorly delimited division of the species is artificial, and both glandular and eglandular forms are sometimes found within individual populations of most species. They also indicated that nevadensis has styles 0.2–0.3 mm (versus 0.05–0.15 mm in D. paradisa), but this distinction is equally unreliable. Indeed, the style length and the presence versus absence of glands are not inherited together. Some of the eglandular plants have styles to 0.1 mm (e.g., Williams & Tiehm 86-51-1, GH). It is likely that some of the plants identified as nevadensis are of hybrid origin involving other species, especially D. nelsonii.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
