Symphyotrichum yukonense

(Cronquist) G. L. Nesom

Phytologia 77: 294. 1995.

Common names: Yukon aster
EndemicConservation concern
Basionym: Aster yukonensis Cronquist Madroño 8: 98. 1945
Synonyms: Virgulus yukonensis (Cronquist) Reveal & Keener
Treatment appears in FNA Volume 20. Treatment on page 485. Mentioned on page 471, 483.

Perennials cespitose or colonial, 5–30 cm; with short, erect, woody caudices from long, thin rhizomes. Stems 1–8+, erect (purplish to brown, slender), villous, more densely so distally, distally moderately stipitate-glandular. Leaves (yellowish to dark green. midrib purplish, often prominent) thin, reduced distally, margins entire; basal withering by flowering, winged-petiolate to subpetiolate (petioles ± sheathing), blades narrowly oblanceolate, 8–15 × 1–3 mm, bases attenuate, margins scabrous, apices obtuse to acute, faces glabrous or glabrate; proximal cauline often withering by flowering, sessile or subsessile, blades linear-oblanceolate, 20–70 × 1–4 mm, bases ± clasping, margins ciliate, apices acute, abaxial faces glabrous or midnerve ± sparsely villous, adaxial glabrous or sparsely villous, midnerves ± villous; distal sessile, blades linear-lanceolate, 10–30 × 1–2.5 mm, bases ± subclasping, ± rounded to subauriculate, margins sometimes stipitate-glandular, apices acute, mucronate or white-spinulose, faces glabrous or sparsely villous, short-stipitate-glandular. Heads usually borne singly, sometimes in open, corymbo-paniculiform arrays, branches ascending. Peduncles ± densely short-villous, ± densely stipitate-glandular, bracts 1–3, foliaceous, reduced. Involucres campanulate, 7–10 mm. Phyllaries in 3–4 (–5) series, linear-lanceolate, subequal, bases scarious, margins hyaline or purplish, scarious, erose, ciliate or short-stipitate-glandular, green zones herbaceous at least distally, often purplish to purple, apices long-acuminate, spreading to reflexed, faces ± densely villous (outer more so), ± densely stipitate-glandular. Ray-florets (8–) 15–30; corollas purple to blue, laminae 5–11 × 0.5–2 mm. Disc-florets 16–38; corollas yellow becoming brown, 4–6.5 mm, lobes triangular, 0.4–0.8 mm. Cypselae brown (sometimes purplish, nerves stramineous), narrowly obovoid, ± compressed, ca. 3 mm, 7–10-nerved, faces sparsely to moderately sericeo-strigose; pappi sordid (barb tips sometimes purplish-tinged), 3.5–4.8 mm. 2n = 10.


Phenology: Flowering Jul–Aug.
Habitat: Mud flats, gravelly, stony or silty lakeshores, sometimes saline areas
Elevation: 300–1500 m

Discussion

Of conservation concern.

Symphyotrichum yukonense is distributed disjunctly on the John River in the southern Brooks Range (Alaska), Lake Kluane (Yukon), and the Mackenzie Mountains and middle Mackenzie River (Northwest Territories). It appears closely related to S. pygmaeum.

Selected References

None.

Lower Taxa

None.

"thin" is not a number."thin" is not a number.

... more about "Symphyotrichum yukonense"
villous +  and glabrous +
not tailed +, rounded +  and obtuse +
subsessile +, sessile +, winged-petiolate +  and subpetiolate +
distinct +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
spreading +  and reflexed +
villous +, glabrous +  and glabrate +
subequal +
scarious +
1mm +  and 4mm +
usually triangular +  and linear +
usually deltate +  and lanceolate +
corymbo-paniculiform +  and open +
indeterminate +  and determinate +
Luc Brouillet +, John C. Semple +, Geraldine A. Allen +, Kenton L. Chambers +  and Scott D. Sundberg† +
(Cronquist) G. L. Nesom +
subclasping +, subsessile +, sessile +, winged-petiolate +  and subpetiolate +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
villous +, glabrous +  and glabrate +
less rounded +  and subauriculate +
scarious +
1mm;4mm +
Aster yukonensis +
subsessile +, sessile +, winged-petiolate +  and subpetiolate +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
villous +, glabrous +  and glabrate +
linear-lanceolate;acute;linear-oblanceolate;obtuse;acute +
1mm;2.5mm +
rugulose +  and muricate +
reduced +
barbellulate +  and barbellate +
Yukon aster +
not 2-lipped +  and actinomorphic +
yellow becoming brown +, purple +  and blue +
at maturity , more or less ampliate , tubes usually shorter +
0.4 cm4 mm <br />0.004 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
compressed +  and obovoid +
fertile +  and bisexual +
fertile +  and bisexual +
N.W.T. +, Yukon +  and Alaska. +
300–1500 m +
subsessile +, sessile +, winged-petiolate +  and subpetiolate +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
sericeo-strigose +, stipitate-glandular +, villous +, short-stipitate-glandular +, glabrous +  and glabrate +
acute;linear-oblanceolate;obtuse;acute +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Mud flats, gravelly, stony or silty lakeshores, sometimes saline areas +
disciform +  and radiate +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
campanulate +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
2.4 cm24 mm <br />0.024 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.5mm;2mm +
sessile +  and petiolate +
cauline +  and basal +
villous +  and glabrous +
reduced +
decurrent +
triangular +
subsessile +, sessile +, winged-petiolate +  and subpetiolate +
purplish +  and hyaline +
20mm;70mm +
short-stipitate-glandular +, ciliate +, stipitate-glandular +, villous +, glabrous +  and glabrate +
acute +, linear-oblanceolate +  and obtuse +
1mm +  and 4mm +
villous +  and glabrous +
2-carpellate +
persistent +
25 +  and 40 +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.48 cm4.8 mm <br />0.0048 m <br />) +
stipitate-glandular +  and short-villous +
Flowering Jul–Aug. +
linear-lanceolate +
styliferous +, neuter +  and pistillate +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
exalbuminous +
Endemic +  and Conservation concern +
branched +  and simple +
1 +  and 8 +
appendaged +  and truncate +
papillate +  and smooth +
Virgulus yukonensis +
Symphyotrichum yukonense +
Symphyotrichum subg. Virgulus +
species +
at maturity , more or less ampliate , tubes usually shorter +
ampliate +
with cormoid caudices +  and rhizomatous +
colonial +  and cespitose +
stipitate-glandular +
5 cm50 mm <br />0.05 m <br /> (30 cm300 mm <br />0.3 m <br />) +
tree +, shrub +  and subshrub +
purplish +  and purple +
lanceolate +  and diamond--shaped +