Rorippa barbareifolia |
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hoary yellow cress |
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Habit | Annuals; (terrestrial or of wet habitat, not submerged); densely villous or sparsely hirsute at least basally, sometimes glabrate distally. |
Stems | (simple from base), erect, branched distally, (2–)3–9.5(–11) dm. |
Basal leaves | rosulate; (petiole 1–7 cm); blade margins lyrate-pinnatifid or subruncinate. |
Cauline leaves | sessile; blade lanceolate to oblanceolate or oblong, 2.5–10(–15) cm × 4–25(–45) mm, base auriculate or amplexicaul, margins: proximal lyrate-pinnatifid, (lobes 2–7 on each side), laciniate, irregularly serrate, repand, or entire, distal undivided and entire or obscurely denticulate, (apex acute). |
Racemes | considerably elongated. |
Flowers | sepals spreading, oblong, 1.6–2.8 × 0.6–1.2 mm; petals yellow, obovate or spatulate, (1.5–)1.8–3(–3.5) × 0.7–1.8(–2) mm; median filaments 1.5–2.5 mm; anthers oblong, 0.5–0.6mm, (gynophore 0.3–0.8(–1) mm). |
Fruiting pedicels | ascending, straight, (2–)4–12(–14) mm, (glabrous or hirsute). |
Fruits | silicles, straight, globose or subglobose, (2.5–)3.5–6(–6.5) × (2.3–)2.8–4(–4.3) mm; valves [(3 or) 4(–6), leathery, not veined], glabrous; (septum fenestrate at middle); ovules 60–85 per ovary; style (stout), 0.5–1(–1.4) mm. |
Seeds | dark reddish brown, oblong-ovate, 0.5–0.7 mm (0.3–0.4 mm diam.), reticulate. |
2n | = 16. |
Rorippa barbareifolia |
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Phenology | Flowering Jun–Aug. |
Habitat | Forest borders, roadsides, waste grounds, moist areas, stream banks, gravel pits |
Elevation | 100-700 m (300-2300 ft) |
Distribution |
AK; SK; YT; e Asia |
Discussion | Rorippa barbareifolia is readily distinguished from other species of the genus by having fruits consistently with more than two valves. Other species (e.g., R. calycina, R. palustris) occasionally show three-valved fruits, but these always appear with more, normal, two-valved fruits on the same plant. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 498. |
Parent taxa | |
Sibling taxa | |
Synonyms | Camelina barbareifolia, Radicula barbareifolia, R. hispida var. barbareifolia, R. islandica var. barbareifolia, Tetrapoma barbareifolium, Tetrapoma pyriforme |
Name authority | (de Candolle) Kitagawa: J. Jap. Bot. 13: 137. (1937) |
Web links |