View source for Potentilla villosula

{{Treatment/ID
|accepted_name=Potentilla villosula
|accepted_authority=Jurtzev in A. I. Tolmatchew
|publications={{Treatment/Publication
|title=in A. I. Tolmatchew, Fl. Arct. URSS
|place=9(1): 319. 1984
|year=1984
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Potentilla villosula subsp. congesta
|authority=Jurtzev
|rank=subspecies
}}
|hierarchy=Rosaceae;Rosaceae subfam. Rosoideae;Rosaceae tribe Potentilleae;Potentilla;Potentilla sect. Niveae;Potentilla villosula
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Rosaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Rosaceae subfam. Rosoideae]]</div><div class="higher-taxon"><small>tribe</small>[[Rosaceae tribe Potentilleae]]</div><div class="higher-taxon"><small>genus</small>[[Potentilla]]</div><div class="higher-taxon"><small>section</small>[[Potentilla sect. Niveae]]</div><div class="higher-taxon"><small>species</small>[[Potentilla villosula]]</div></div>
|volume=Volume 9
|mention_page=page 196, 197
|treatment_page=page 202
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>densely tufted. <b>Caudex</b> branches stout, sometimes ± columnar, not sheathed with marcescent whole leaves. <b>Stems</b> ascending to erect, 0.2–1.5(–2) dm, lengths 1.5–3(–4) times basal leaves. <b>Basal</b> leaves 1–5.5(–7) cm; petiole 0.5–3.5(–5) cm, long hairs common to dense, ascending to spreading, loosely appressed, sometimes retrorse, 1–2(–3) mm, soft, smooth, crisped/short-cottony hairs usually sparse, sometimes common, glands absent or sparse to common or obscured; leaflets overlapping, central broadly obovate to obtriangular, 0.8–2.5 × 0.6–2 cm, sessile to subsessile, base broadly cuneate, margins revolute, distal 1/2–2/3(–3/4) incised ± 1/2 to midvein, teeth 2–3(–4) per side, ± approximate to ± distant, surfaces ± dissimilar, abaxial grayish to white or yellowish white, long hairs 1.5–2.5 mm, cottony-crisped hairs ± dense, adaxial grayish green, long hairs abundant to dense, crisped hairs absent, sparse, or obscured. <b>Cauline</b> leaves (0–)1–2(–3). <b>Inflorescences</b> (1–)2–3(–4)-flowered. <b>Pedicels</b> 0.5–3(–5) cm in flower, to 4(–6) cm in fruit. <b>Flowers</b>: epicalyx bractlets broadly lanceolate to narrowly ovate, 3–7(–8) × 1.5–3(–3.5) mm, 2/3 to as wide as sepals, margins ± revolute, red glands absent; hypanthium (3–)4–6 mm diam.; sepals 4–7(–8) mm, apex acute or rarely acuminate; petals 5–10 × 6–12 mm, significantly longer than sepals; filaments 1.1–1.4 mm, anthers 0.5–0.8 mm; carpels 40–70, apical hairs absent or sparse (straight), styles narrowly columnar to conic-tapered, papillate-swollen in proximal 1/5 or less, 1–1.2 mm. <b>Achenes</b> 0.9–2 mm. <b>2n</b> = 28 (Russian Far East).</span><!--

-->{{Treatment/Body
|phenology=Flowering late spring to summer.
|habitat=Rocky alpine heaths, outcrops, scree and talus, gravel outwash plains, dry tundra, coastal bluffs, stabilized sand dunes, mostly on acidic bedrock
|elevation=0–2900 m
|distribution=Alta.;B.C.;Yukon;Alaska;e Asia (Russian Far East).
|discussion=<p><i>Potentilla villosula</i> was included previously in <i>P. villosa</i>; the two overlap in the southern and western Alaskan coasts, where a transition is suspected to be associated with differing ploidy levels. The plants from this area with silky hairs and multiflowered inflorescences are assigned to <i>P. villosa</i>; <i>P. villosula</i> has thicker, stiffer, and less silky hairs, fewer teeth per leaflet, narrower bracts, fewer and smaller flowers with narrower epicalyx bractlets and sepals, and fewer achenes (sometimes with single apical hairs). While <i>P. villosa</i> is restricted to relatively rocky sites near the coast from western Alaska to Oregon, <i>P. villosula</i> often occurs on coastal sand dunes, farther inland, and/or farther to the north.</p><!--
--><p>As circumscribed, <i>Potentilla villosula</i> is a major plant of Alaska, especially of the Bering Sea region. The species extends from Alaska and the Yukon to at least central British Columbia. Most of the range given by E. Hultén (1968) for <i>P. villosa</i> belongs to <i>P. villosula</i>. W. J. Cody (1996) accepted the name <i>P. villosula</i> for a common south-central Yukon plant, but the majority of the plants mapped by Cody probably belong to <i>P. subgorodkovii</i> (although the distinction between the two species needs more resolution). Provisionally included here are plants from southern and central Yukon south through the Canadian Rockies, possibly including the type of <i>P. nivea</i> <i></i>subsp.<i> fallax</i> A. E. Porsild. Such plants tend to be significantly smaller overall than Alaskan <i>P. villosula</i>; at least some have straight hairs on carpel apices.</p><!--
--><p>J. Soják (2004) believed that <i>Potentilla villosula</i> evolved from crosses between <i>P. villosa</i> and <i>P. vulcanicola</i>. The affinity with <i>P. villosa</i> is seen in the sericeous vestiture, number of leaflet teeth, and flower number and size, and with <i>P. vulcanicola</i> in the frequent occurrence of straight hairs on carpel apices in both species. Plants with columnar caudex branches, representing a significant part of the Alaskan material, have been called <i></i>subsp.<i> congesta</i>. This morphology results from the persistence of marcescent whole leaves for several years (in typical <i>P. villosula</i> only sheaths and petioles are retained). This character suggests that <i>P. subvahliana</i>, with which the form called <i></i>subsp.<i> congesta</i> is sympatric, may be part of its parentage. <i>Potentilla villosula</i> is accepted here in a fairly collective sense, possibly including several hybrid lineages, but with <i>P. villosa</i> a part of them all.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Potentilla villosula
|authority=Jurtzev in A. I. Tolmatchew
|rank=species
|parent rank=section
|synonyms=Potentilla villosula subsp. congesta
|basionyms=
|family=Rosaceae
|phenology=Flowering late spring to summer.
|habitat=Rocky alpine heaths, outcrops, scree and talus, gravel outwash plains, dry tundra, coastal bluffs, stabilized sand dunes, mostly on acidic bedrock
|elevation=0–2900 m
|distribution=Alta.;B.C.;Yukon;Alaska;e Asia (Russian Far East).
|reference=None
|publication title=in A. I. Tolmatchew, Fl. Arct. URSS
|publication year=1984
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-data-curation.git/src/bb6b7e3a7de7d3b7888a1ad48c7fd8f5c722d8d6/coarse_grained_fna_xml/V9/V9_306.xml
|subfamily=Rosaceae subfam. Rosoideae
|tribe=Rosaceae tribe Potentilleae
|genus=Potentilla
|section=Potentilla sect. Niveae
|species=Potentilla villosula
}}<!--

-->[[Category:Treatment]][[Category:Potentilla sect. Niveae]]