Difference between revisions of "Douglasia alaskana"

(Coville & Standley ex Hultén) S. Kelso

Canad. J. Bot. 70: 595. 1992,.

Basionym: Androsace alaskana Coville & Standley ex Hultén Fl. Alaska Yukon 8: 1279. 1948
Synonyms: Androsace alaskana var. reediae S. L. Welsh & Goodrich
Treatment appears in FNA Volume 8. Treatment on page 264. Mentioned on page 263, 265.
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Revision as of 20:29, 24 September 2019

Plants biennial, not mat- or cushion-forming. Stems ascending, without marcescent leaves. Leaves in single rosette, horizontal, thin; blade cuneate to oblong, 5–15 × 3–8 mm, margins entire, shortly ciliolate, hairs simple, apex acute or remotely 3-toothed, ciliate, hairs simple, abaxial surface densely villous, hairs simple, adaxial surface glabrous or sparsely villous. Scapes to 10 mm in early anthesis, elongating to 1–10 cm in fruit, densely hairy at apex, hairs branched and stellate. Inflorescences 1–2-flowered, usually bracteate, sometimes ebracteate; bracts 1–5, lanceolate, 3–5 × 3–5 mm, glabrous. Pedicels absent. Flowers: calyx 3–6 × 3–4 mm, glabrous; corolla deep purple, white in age, limb 3–5 mm diam., lobes 1–3 × 1 mm, margins entire. 2n = 38.


Phenology: Flowering early summer.
Habitat: Stony places on tundra, alpine scree
Elevation: 0-2000 m

Discussion

The single rosettes of Douglasia alaskana are not characteristic of any other species of the genus; they are common in Androsace sect. Aretia, where annual/biennial growth habit appears to have evolved multiple times. Chromosome number, pubescence, and seed anatomy (A. A. Anderberg and S. Kelso 1996) link this taxon to other species of Douglasia. Plants described as var. reediae differ only in the marginally thinner scapes and less noticeably toothed leaves. Because this variation is well within that shown by the species throughout its range in western and southern Alaska, the variety is not recognized here. Douglasia alaskana is widespread but somewhat uncommon in the mountains of southern Alaska and southern Yukon; disjunct populations occur in western Alaska on the Seward Peninsula. Presence in British Columbia was suggested by a misidentified specimen (Carney s.n., 13 Jun 1976, V) from Atlin Lake; D. alaskana is not yet known from that province.

Selected References

None.

Lower Taxa

None.