Braya humilis subsp. porsildii |
Braya |
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Porsild's dwarf braya |
northern-rockcress |
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Habit | Perennials; (sometimes pulvinate, caudex simple or many-branched); scapose or not; usually pubescent or pilose, sometimes glabrous, trichomes short-stalked, forked, subdendritic, or submalpighiaceous, mixed with simple ones (rarely exclusively). | |||||||||||||||||||||||||
Stems | ascending to erect or, rarely, decumbent, usually unbranched, 0.3–1.7(–2.5) dm, densely pubescent. |
erect to decumbent or ascending, unbranched or branched. |
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Leaves | blade margins usually entire, sometimes weakly sinuate-dentate, surfaces densely pubescent. |
basal and, sometimes, cauline; petiolate or sessile; basal rosulate, petiolate, blade margins entire, sinuate, dentate, or, rarely, pinnately lobed; cauline usually absent, rarely few present, (sub)sessile, blade margins usually entire, rarely dentate or pinnately lobed. |
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Racemes | (corymbose, sometimes bracteate basally or throughout), elongated or not in fruit. |
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Flowers | petals white, 4.4–6.9 × (1.9–)2.3–4.2 mm. |
sepals [sometimes persistent], oblong [ovate], lateral pair not saccate basally (sometimes slightly so in B. humilis and B. linearis); petals white, pink, or purple [rarely pale yellow], obovate, oblanceolate, or spatulate, (slightly to much longer than sepals), claw distinct or not, (shorter than sepal, apex obtuse or rounded); stamens tetradynamous; filaments dilated or not basally; anthers ovate or oblong, (apex usually obtuse, sometimes apiculate); nectar glands (4), lateral, 1 on each side of lateral stamen. |
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Fruiting pedicels | erect, divaricate, or ascending, slender (much narrower than fruit). |
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Fruits | often abortive, somewhat torulose, 0.8–1.2 mm wide when fully developed; septum not fenestrate or split longitudinally. |
siliques or silicles, sessile, linear, oblong, cylindrical, oval-elliptic, ovoid, lanceoloid, lanceoloid-subulate, or globose, smooth or torulose, terete or slightly latiseptate; valves each often with prominent midvein, glabrous or pubescent; replum rounded; septum complete, (membranous, translucent); ovules (5–)14–44 per ovary; stigma capitate, entire or slightly 2-lobed. |
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Seeds | plump, not winged, oblong or ovoid; seed coat (minutely reticulate), not mucilaginous when wetted; cotyledons incumbent. |
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x | = 7. |
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2n | = 28. |
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Braya humilis subsp. porsildii |
Braya |
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Phenology | Flowering May–Jul. | |||||||||||||||||||||||||
Habitat | Dry alpine scree slopes, glacial moraines, and gravel bars, often on limestone gravels and soils | |||||||||||||||||||||||||
Elevation | 500-3000 m (1600-9800 ft) | |||||||||||||||||||||||||
Distribution |
AB; BC; NT |
North America; n Europe; Asia |
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Discussion | Subspecies maccallae and porsildii share the large flowers, high percentage of abortive fruits, and leaf margins mostly entire, but they differ in indumentum and habitats. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 17 (7 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 7, p. 550. | FNA vol. 7, p. 546. | ||||||||||||||||||||||||
Parent taxa | ||||||||||||||||||||||||||
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Synonyms | Platypetalum | |||||||||||||||||||||||||
Name authority | J. G. Harris: Novon 16: 348. (2006) | Sternberg & Hoppe: Denkschr. Königl.-Baier. Bot. Ges. Regensburg 1(1): 65. (1815) | ||||||||||||||||||||||||
Web links |