Descurainia sophia |
Descurainia sophioides |
|
---|---|---|
fine-leaf tansy-mustard, fixweed, flixweed, flixweed tansymustard, herb sophia, not much flower, tansy mustard |
northern tansy-mustard |
|
Habit | Annuals; eglandular; sparsely to densely pubescent, sometimes glabrous distally, trichomes dendritic. | Annuals or biennials; eglandular or glandular distally; glabrate to moderately pubescent, trichomes dendritic, sometimes mixed with simple ones. |
Stems | erect, unbranched or branched distally, (1–)2–7(–10) dm. |
erect, unbranched or sometimes branched distally, (0.5–)1.5–11(–18) dm. |
Basal leaves | 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 0.5–5 cm; blade pinnate or, sometimes, 2-pinnate, broadly oblanceolate to ovate in outline, 2.5–11.4(–15.2) cm, lateral lobes lanceolate, (to 10 × 4 mm), margins incised. |
Cauline leaves | 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 often glabrous or sparsely pubescent. |
Racemes | considerably elongated in fruit. |
elongated or not in fruit, (flowers overtopped by developing fruits). |
Flowers | 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 erect, yellowish, oblong, 1.6–2.7 mm, glabrous; petals narrowly oblanceolate, 2–2.5 × 0.3–0.6 mm; median filaments 2.5–3.5 mm; anthers 0.3–0.4 mm. |
Fruiting pedicels | divaricate to ascending, straight, (5–)8–15(–20) mm. |
divaricate to ascending, (often recurved in age), slender, (3–)4–9(–13) mm. |
Fruits | 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 widely spreading, narrowly linear, slightly torulose, (9–)14–30(–34) × 0.6–1.1 mm, (usually terete, rarely slightly flattened, often curved inward); valves each with obscure midvein; septum not veined; ovules 30–62 per ovary; style obsolete, 0.07–0.3 mm, glabrous. |
Seeds | uniseriate, reddish brown, oblong, 0.7–1.3 × 0.3–0.6 mm. |
uniseriate, light brown, narrowly oblong, 1–1.5 × 0.3–0.5 mm. |
2n | = 28. |
= 14. |
Descurainia sophia |
Descurainia sophioides |
|
Phenology | Flowering Mar–Jul. | Flowering Jun–Sep. |
Habitat | Roadsides, waste places, disturbed sites, railroad embankments, hillsides, mountain slopes, canyon bottoms, stream banks, fields, lawns, pastures, deserts, sagebrush and pinyon-juniper communities | Open meadows, eroded peat, roadsides, disturbed and waste sites, rocky outcrops, mining dumps, gravelly grounds, stream banks, gullies |
Elevation | 0-3000 m (0-9800 ft) | 0-1000 m (0-3300 ft) |
Distribution |
AK; AR; AZ; CA; CO; CT; DC; DE; GA; IA; ID; IL; IN; KS; KY; LA; MA; ME; MI; MN; MO; MT; NC; ND; NE; NH; NM; NV; NY; OK; OR; PA; RI; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; NT; ON; PE; QC; SK; YT; Eurasia [Introduced in North America; introduced also in Mexico, Central America, South America, South Africa, Australia]
|
AK; BC; MB; NT; NU; YT; Asia (Russian Far East, Siberia) |
Discussion | 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.) |
|
Source | FNA vol. 7, p. 528. | FNA vol. 7, p. 529. |
Parent taxa | Brassicaceae > tribe Descurainieae > Descurainia | Brassicaceae > tribe Descurainieae > Descurainia |
Sibling taxa | ||
Synonyms | Sisymbrium sophia, Hesperis sophia, Sisymbrium parviflorum, Sophia parviflora | Sisymbrium sophioides, Hesperis arctica, Sisymbrium arcticum, Sophia sophioides |
Name authority | (Linnaeus) Webb ex Prantl: in H. G. A. Engler and K. Prantl, Nat. Pflanzenfam. 55(III,2): 192. (1891) | (Fischer ex Hooker) O. E. Schulz: in H. G. A. Engler, Pflanzenr. 86[IV,105]: 316. (1924) |
Web links |
|