Braya humilis subsp. maccallae |
Brassicaceae tribe Euclidieae |
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dwarf braya, maccall's dwarf braya, mccalla's dwarf braya |
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Habit | Annuals or perennials [shrubs or subshrubs]; eglandular. | |
Stems | ascending to erect, often unbranched, 0.4–2.3 dm, moderately pubescent. |
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Leaves | blade margins entire or, sometimes, sinuate-dentate, surfaces glabrescent to moderately pubescent. |
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Cauline leaves | (sometimes absent), usually petiolate or sessile, sometimes subsessile; blade base not auriculate, margins usually entire or dentate, rarely lobed. |
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Trichomes | short-stalked or sessile, stellate, forked, dendritic, malpighiaceous, or simple, rarely absent. |
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Racemes | usually ebracteate, usually elongated in fruit. |
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Flowers | petals white, (4.4–)4.9–6.7(–7.2) × (2.1–)2.3–4(–4.2) mm. |
actinomorphic; sepals erect [ascending to spreading], lateral pair seldom saccate basally; petals white, pink, or purple [yellow], claw present, distinct or obscure; filaments unappendaged, not winged; pollen 3-colpate. |
Fruits | often abortive, somewhat torulose, 0.7–1.2 mm wide when fully developed; septum not fenestrate or split longitudinally. |
silicles or siliques, usually dehiscent, unsegmented, terete or latiseptate [angustiseptate]; ovules 2–80[–numerous] per ovary; style distinct or obsolete; stigma entire or strongly 2-lobed. |
Seeds | usually biseriate or uniseriate (aseriate in Euclidium); cotyledons accumbent or incumbent. |
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2n | = 28. |
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Braya humilis subsp. maccallae |
Brassicaceae tribe Euclidieae |
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Phenology | Flowering May–Jul. | |
Habitat | Sandy gravelly riverbanks and floodplains, sometimes on slopes and glacial moraines | |
Elevation | 1500-3000 m (4900-9800 ft) | |
Distribution |
AB; BC |
North America; Europe; Asia; n Africa |
Discussion | Subspecies maccallae differs from subspp. elesmerensis and humilis in having leaf margins mostly entire, flowers exceptionally large, and a high percentage of abortive fruit. Cauline leaves are much reduced and arise from the base of the stem, giving an almost acaulescent appearance to the plant. Breeding studies (J. G. Harris 1985) indicate that subspp. maccallae and porsildii are self-incompatible, while most subspecies of Braya humilis are strongly autogamous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera 13, species 115 (3 genera, 9 species in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 550. | FNA vol. 7, p. 545. |
Parent taxa | ||
Sibling taxa | ||
Subordinate taxa | ||
Name authority | J. G. Harris: Novon 16: 346. (2006) | de Candolle: Mém. Mus. Hist. Nat. 7: 236. (1821) |
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