Descurainia sophia
Descurainia pinnata
fine-leaf tansy-mustard, fixweed, flixweed, flixweed tansymustard, herb sophia, not much flower, tansy mustard
green tansy-mustard, intermediate tansymustard, salty tansymustard, short-fruit tansymustard, short-fruit western tansymustard, western tansy-mustard, yellow tansy mustard
erect, unbranched or branched distally, (1–)2–7(–10) dm.
erect, unbranched or branched basally and/or distally, (0.8–)1.3–5.7(–9.2) dm.
petiole 0.1–2(–3) cm;
blade 2- or 3-pinnate, ovate or oblong to obovate in outline, to 15 cm, lateral lobes linear or oblong, (to 10 × 2 mm), margins entire.
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.
sessile or shortly petiolate;
blade smaller distally, distal lobes often narrower, surfaces often glabrous.
sessile or shortly petiolate;
blade smaller distally, distal lobes often narrower, surfaces densely pubescent.
considerably elongated in fruit.
considerably elongated in fruit.
sepals erect to ascending, yellowish, oblong, 1.8–2.8 mm, glabrate to sparsely pubescent;
petals narrowly oblanceolate, 2–3 × 0.4–0.6 mm;
median filaments 2–3 mm;
anthers 0.3–0.4 mm.
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.
divaricate to ascending, straight, (5–)8–15(–20) mm.
usually ascending to divaricate or horizontal, rarely descending (at 20–110º angle), straight or slightly recurved, 4–18(–23) mm.
divaricate-ascending to erect, narrowly linear, torulose, (12–)15–27(–30) × 0.5–0.8(–1) mm, (straight or curved upward);
valves each with distinct midvein;
septum with a broad central longitudinal band appearing as 2 or 3 veins;
ovules 20–48 per ovary;
style obsolete, 0.05–0.2 mm, glabrous.
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.
uniseriate, reddish brown, oblong, 0.7–1.3 × 0.3–0.6 mm.
biseriate, reddish brown, oblong, 0.6–0.9 × 0.4–0.5 mm.
= 28.
Descurainia sophia
Descurainia pinnata
Deviant chromosome counts (e.g., 2n = 12, 14, 20, 38; see R. C. Rollins 1993, N. H. Holmgren 2005b, S. I. Warwick and I. A. Al-Shehbaz 2006) are most certainly erroneous, and the species appears to be exclusively tetraploid based on x = 7.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Subspecies 4 (4 in the flora).
Plants assigned to Descurainia pinnata by various authors represent one of the most complex assemblages of any North American Brassicaceae. L. E. Detling (1939) divided it into eleven subspecies, of which R. C. Rollins (1993) accepted eight. The species includes series of populations that show tremendous variability in every conceivable character, and the variation is continuous between extremes. Some of the taxa recognized by these authors were based solely on trivial variations in the degree of pubescence on the distal parts, shape of the distalmost leaf segments, and presence or absence of glands. The latter character can vary within a given population and, therefore, its utility in distinguishing taxa is questionable at best. Cases in point are Cully s.n. (spring 1984) and Worthington 26353, both at UNM, collected from Bernalillo and Luna counties (New Mexico), respectively; each sheet has both glandular and eglandular forms.
As delimited by L. E. Detling (1939) and R. C. Rollins (1993), subspp. halictorum and menziesii represent a heterogeneous assemblage of intermediates within Descurainia pinnata and between it and other species. In the absence of thorough studies on these subspecies, we prefer to avoid placing them in the synonymy of a putative parental species or recognizing them as subspecies of a parent. Readers interested in the synonymies of subspp. halictorum and menziesii may consult Detling and Rollins.
Molecular studies by B. E. Goodson (2007) indicated that some taxa previously included in Descurainia pinnata (i.e., subspp. filipes, nelsonii, paradisa, and paysonii) should be placed elsewhere. While the molecular data were not able to resolve the remaining subspecies, a critical evaluation of morphology shows that the entire D. pinnata complex falls into at least four relatively distinct groups recognized here as subspecies.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Rachises glabrous, eglandular. | subsp. glabra |
1. Rachises sparsely to densely pubescent, glandular or eglandular | → 2 |
2. Plants canescent, often eglandular; stems branching basally or distal to base; sepals purple or rose. | subsp. ochroleuca |
2. Plants not canescent, often glandular; stems unbranched basally; sepals yellow or rose | → 3 |
3. Fruiting pedicels 4-14(-17) mm, forming (60-)70-90(-110)º angles; sepals rose (at least apically), 0.8-2 mm; petals 1-1.8 mm. | subsp. pinnata |
3. Fruiting pedicels (7-)10-18(-23) mm, forming 20-60(-80)º angles; sepals yellow, 1.5-2.6 mm; petals (1.7-)2-3 mm. | subsp. brachycarpa |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria, 
SW CO Wildflowers 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
- Local floras: BC, CA, OR, WA
- Local Web sites: CalFlora, CalPhotos, Flora NW, Go Botany, IL Wildflowers, KS Wildflowers, LA Plants, MI Flora, MN Wildflowers, MO Plants, PNW Herbaria, Turner Photog.
- WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
