Symphyotrichum robynsianum |
Symphyotrichum pygmaeum |
|
---|---|---|
aster à longues feuilles, longleaf aster, Robyns' aster |
pygmy aster |
|
Habit | Perennials, 10–80 cm, colonial; long-rhizomatous. | Perennials 1.5–15 cm, cespitose; with short, branched caudices, long-rhizomatous (both wiry). |
Stems | 1, erect (± flexuous, often reddish), glabrous, hairy in lines distally. |
1–10+, decumbent to ascending (purple), sparsely or densely villous to woolly distally. |
Leaves | stiff, margins sparsely serrulate or entire, ± revolute, scabrous, apices acute to acuminate, mucronulate, faces glabrous, sometimes midveins hairy; basal withering by flowering, long-petiolate, petioles narrowly winged, bases sheathing, blades lanceolate, ca. 20 × 3–5 mm, slightly attenuate to narrowly cuneate; proximal cauline withering by flowering, sessile or subpetiolate, blades linear-lanceolate to -oblanceolate, 100–200 × 4–8 mm, bases cuneate to attenuate, clasping; distal sessile, blades linear-lanceolate to linear, 10–110 × 1–7 mm, progressively reduced distally, bases cuneate to rounded, slightly clasping or not, margins entire. |
firm, margins usually entire, sometimes remotely pauci-serrulate, sparsely villoso-ciliate, apices obtuse to acute, sometimes mucronate; basal often withering by flowering, petiolate (petioles widely winged, sheathing), blades spatulate, 5–19 × 2–4 mm, bases attenuate, apices rounded, faces glabrous or sparsely villous proximally; proximal sessile, blades lanceolate to oblong-lanceolate or (sometimes) -spatulate, 30–50 × 3–10 mm, bases ± clasping, apices obtuse to acute, faces glabrous or sparsely villous; distal sessile, blades lanceolate to oblong, 13–19 × 2–4.5 mm, bases clasping to cuneate, apices acute to obtuse, faces sparsely woolly, sometimes sparsely stipitate-glandular. |
Peduncles | glabrous or ± densely pilose in lines, bracts 1–4, linear, sometimes inrolled distally, clasping, ciliate, distal 1–2 often subtending and surpassing involucres. |
densely villous to lanate distally, bracts 0. |
Involucres | campanulate, 5–8.5 mm. |
hemispherico-campanulate, 9–12.5 mm. |
Ray florets | 20–35; corollas dark blue-violet, seldom white, laminae 8–13 × 1–1.5 mm. |
16–28; corollas purple to violet, laminae 12–18 × 2–3.2 mm. |
Disc florets | (18–)23–40; corollas yellow, 4–6.5 mm, tubes shorter than funnelform throats, lobes lanceolate, 0.8–1 mm. |
53–55; corollas yellow, 5.6–6.5 mm, throats funnelform, lobes triangular, 0.5–0.8 mm (red or white clavate-hairy). |
Phyllaries | in 3–4 series, oblong-lanceolate, subequal, bases indurate 1/3–3/4, margins scarious, erose, hyaline, ciliate proximally, sparsely ciliolate distally, green zones lanceolate to linear, sometimes outer ± foliaceous, apices acuminate to long-acuminate, often foliaceous, mucronate to apiculate, faces glabrous, eglandular. |
in 3–4 series (dark purple), lance-oblong or oblong (outer) to linear-lanceolate or sometimes linear (inner), subequal, outer ± herbaceous, bases not indurate, margins herbaceous (outer) to narrowly scarious and erose proximally (inner), strongly purple, villoso-ciliate in green portion, green zones (inner) 1/2–2/3 of distal portions, apices acute to acuminate, inner sometimes apiculate, appressed to loose and squarrose (particularly outer), faces woolly to densely villous, sparsely to moderately stipitate-glandular. |
Heads | in elongate, open, narrow, paniculiform or racemiform arrays, branches ascending, short, leafy, branch leaves smaller and reduced distally (heads 1–3 per branch). |
borne singly. |
Cypselae | tan, obovoid, compressed, ca. 2.2–2.4 mm, 5–6-nerved, faces sparsely strigillose; pappi pinkish, 7–8 mm. |
fusiform to cylindro-obconic, ± compressed, [size unknown], 4–7-nerved (faint), faces ± densely strigillose; pappi whitish to yellowish, 5–7.2 mm. |
2n | = 64, 80. |
|
Symphyotrichum robynsianum |
Symphyotrichum pygmaeum |
|
Phenology | Flowering Aug–Sep. | Flowering summer. |
Habitat | Wet or damp, open, sandy, gravelly, or rocky grounds, often calcareous, cracks in rocky stream or lake shores, limestone alvars, seasonally wet glades and swales, jackpine outwash plains | Open, active, moist sand dunes, sandy or silty stream banks and terraces, usually cyclically disturbed gravelly tundra and tundra slopes |
Elevation | 10–400 m (0–1300 ft) | 0–200+ m (0–700+ ft) |
Distribution |
MI; MN; WI; MB; ON; QC
|
AK; NT; NU |
Discussion | The name Aster longifolius Lamarck has been misapplied to this taxon. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Symphyotrichum pygmaeum has long been included within or associated with Eurybia sibirica. Though similar in appearance, the two species can be distinguished by the glands present on S. pygmaeum on the distal leaves and phyllaries. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 530. | FNA vol. 20, p. 485. |
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus |
Sibling taxa | ||
Synonyms | Aster robynsianus | Aster pygmaeus, Aster sibiricus subsp. pygmaeus, Aster sibiricus var. pygmaeus, Eurybia pygmaea |
Name authority | (J. Rousseau) Brouillet & Labrecque: Phytologia 82: 138. (1997) | (Lindley) Brouillet & S. Selliah: Sida 21: 1635. (2005) |
Web links |