Symphyotrichum nahanniense

(Cody) Semple in J. C. Semple et al.

in J. C. Semple et al., Cult. Native Asters Ontario, 134. 2002.

Common names: Nahanni aster
EndemicConservation concern
Basionym: Aster nahanniensis Cody Naturaliste Canad. 101: 888. 1974
Treatment appears in FNA Volume 20. Treatment on page 523. Mentioned on page 468, 477, 501.

Perennials, 7–39 cm, cespitose; slender, woody, short-rhizomatous (rhizomes of season shallow or deep-seated, not producing rosettes near parent stems). Stems 1, ascending to decumbent (slender, green to reddish-brown), glabrate or sparsely short woolly-pilose in lines or zones, more densely so distally. Leaves (light green, abaxial sometimes becoming much darker) thin to firm, margins entire, scabrous, apices mucronulate, faces glabrous; basal persistent or withering by flowering, petiolate, blades oblanceolate to short-spatulate, 10–130 × 2–8 mm, bases cuneate to attenuate, margins rarely sparsely serrulate, apices obtuse, faces glabrous; proximal cauline persistent or withering by flowering, sessile, blades oblanceolate to linear-lanceolate, 13–60 × 2–6 mm, bases ± clasping, apices acute; distal sessile, blades linear to linear-lanceolate, 10–36 × 1–4 mm, reduced distally, bases subauriculate, subclasping to ± clasping. Heads usually borne singly or in open, paniculiform arrays (sometimes terminating lateral branches arising from decumbent stems or from proximal stem branches), branches few. Peduncles 10–70 mm, sparsely to moderately short-strigose, bracts 0–10, lanceolate, often foliaceous, reduced distally. Involucres cylindro-campanulate, 4.7–7.4 mm. Phyllaries in 3–4 series, outer spatulate, inner lanceolate, ± unequal to subequal, bases indurate, margins reddish, papery, erose-ciliate, green zones lanceolate, apices acute, faces glabrous. Ray-florets 15–41; corollas white to pale rose, often becoming rose-violet, laminae 5–13 × 0.7–1.8 mm. Disc-florets 20–60; corollas yellow turning reddish with age, 3.7–6.6 mm, tubes shorter than funnelform throats, lobes erect to spreading, lanceolate, 0.4–0.8 mm. Cypselae tan (nerves stramineous), obovoid, compressed, 2–3 mm, 3–5-nerved, faces strigillose; pappi white, 4–6.5 mm. 2n = 16.


Phenology: Flowering Aug–Sep.
Habitat: Stream banks near hot mineral springs
Elevation: ± 1000 m

Discussion

Of conservation concern.

Symphyotrichum nahanniense is known only from the South Nahanni River (Mackenzie Mountains), Nahanni National Park.

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

not tailed +, rounded +  and obtuse +
sessile +  and petiolate +
distinct +
1.3 cm13 mm <br />0.013 m <br /> (6 cm60 mm <br />0.06 m <br />) +
subequal +
scarious +
2mm +  and 6mm +
usually triangular +  and linear +
usually deltate +  and lanceolate +
paniculiform +  and open +
indeterminate +  and determinate +
Luc Brouillet +, John C. Semple +, Geraldine A. Allen +, Kenton L. Chambers +  and Scott D. Sundberg† +
(Cody) Semple in J. C. Semple et al. +
subclasping +  and more or less clasping +
1.3 cm13 mm <br />0.013 m <br /> (6 cm60 mm <br />0.06 m <br />) +
subauriculate +, acute +, oblanceolate +  and linear-lanceolate +
indurate +
2mm;6mm +
Aster nahanniensis +
sessile +  and petiolate +
1 cm10 mm <br />0.01 m <br /> (3.6 cm36 mm <br />0.036 m <br />) +
linear;linear-lanceolate +
reduced +
1mm;4mm +
rugulose +  and muricate +
lanceolate +
reduced +
barbellulate +  and barbellate +
sessile +  and petiolate +
Nahanni aster +
not 2-lipped +  and actinomorphic +
yellow turning reddish +, rose-violet +, white +  and pale rose +
at maturity , more or less ampliate , tubes usually shorter +
0.37 cm3.7 mm <br />0.0037 m <br /> (0.66 cm6.6 mm <br />0.0066 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
strigillose +  and glabrous +
compressed +  and obovoid +
fertile +  and bisexual +
fertile +  and bisexual +
± 1000 m +
1 cm10 mm <br />0.01 m <br /> (13 cm130 mm <br />0.13 m <br />) +
strigillose +  and glabrous +
obtuse;cuneate;attenuate +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Stream banks near hot mineral springs +
disciform +  and radiate +
in open , paniculiform arrays +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
less unequal +  and subequal +
0.4 cm4 mm <br />0.004 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
cylindro-campanulate +
0.47 cm4.7 mm <br />0.0047 m <br /> (0.74 cm7.4 mm <br />0.0074 m <br />) +
1.8 cm18 mm <br />0.018 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
2 (?) +  and 5 (?) +
0.7mm;1.8mm +
sessile +  and petiolate +
cauline +  and basal +
decurrent +
erect;spreading +
lanceolate +
serrulate +  and entire +
10mm;130mm +
obtuse +, cuneate +  and attenuate +
2mm +  and 8mm +
2-carpellate +
persistent +
25 +  and 40 +
0.4 cm4 mm <br />0.004 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
short-strigose +
1 cm10 mm <br />0.01 m <br /> (7 cm70 mm <br />0.07 m <br />) +
Flowering Aug–Sep. +
oblanceolate or spatulate +  and linear +
strongly unequal +  and subequal +
in J. C. Semple et al., Cult. Native Asters Ontario, +
styliferous +, neuter +  and pistillate +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
exalbuminous +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.1mm;0.2mm +
Endemic +  and Conservation concern +
branched +  and simple +
ascending +  and decumbent +
appendaged +  and truncate +
papillate +  and smooth +
Aster sect. Heterastrum +  and Aster subg. Symphyotrichum +
Symphyotrichum nahanniense +
Symphyotrichum sect. Symphyotrichum +
species +
funnelform-campanulate +  and cylindric +
ampliate +
7 cm70 mm <br />0.07 m <br /> (39 cm390 mm <br />0.39 m <br />) +
tree +, shrub +  and subshrub +
lanceolate +