Braya humilis subsp. ellesmerensis |
Braya humilis subsp. maccallae |
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dwarf braya, maccall's dwarf braya, mccalla's dwarf braya |
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Stems | usually ascending (prostrate in fruit), unbranched, 0.3–1.6 dm, moderately pubescent. |
ascending to erect, often unbranched, 0.4–2.3 dm, moderately pubescent. |
Leaves | blade margins pinnatifid or entire, surfaces moderately pubescent. |
blade margins entire or, sometimes, sinuate-dentate, surfaces glabrescent to moderately pubescent. |
Flowers | petals white or purple-tinged, (3–)4–5.6 × (1.3–)2–3.3(–3.8) mm. |
petals white, (4.4–)4.9–6.7(–7.2) × (2.1–)2.3–4(–4.2) mm. |
Fruits | usually fertile and fully developed, not or weakly torulose, (1–)1.2–1.8(–2) mm wide; septum often fenestrate (with circular perforations at regular intervals longitudinally or with a narrow, elliptical, longitudinal split at base or both). |
often abortive, somewhat torulose, 0.7–1.2 mm wide when fully developed; septum not fenestrate or split longitudinally. |
2n | = 42. |
= 28. |
Braya humilis subsp. ellesmerensis |
Braya humilis subsp. maccallae |
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Phenology | Flowering Jun–Jul, fruiting Jul–Aug. | Flowering May–Jul. |
Habitat | Sand, clay, and gravel slopes and plains | Sandy gravelly riverbanks and floodplains, sometimes on slopes and glacial moraines |
Elevation | 0-200 m (0-700 ft) | 1500-3000 m (4900-9800 ft) |
Distribution |
NU |
AB; BC |
Discussion | Prostrate fruiting stems, exceptionally broad, non-torulose fruits, and fenestrate silique septae distinguish subsp. ellesmerensis from other subspecies of Braya humilis. It is known only from northern Ellesmere Island. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 7, p. 550. | FNA vol. 7, p. 550. |
Parent taxa | ||
Sibling taxa | ||
Name authority | J. G. Harris: Novon 16: 345. (2006) | J. G. Harris: Novon 16: 346. (2006) |
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