Symphyotrichum porteri

(A. Gray) G. L. Nesom

Phytologia 77: 289. 1995.

Common names: Porter’s or smooth white aster
Endemic
Basionym: Aster porteri A. Gray Notes Compositae, 99. 1880
Synonyms: Aster ericoides var. strictus Porter
Treatment appears in FNA Volume 20. Treatment on page 513. Mentioned on page 468, 500.

Perennials, 10–50 cm, cespitose; usually with branched caudices, sometimes long-rhizomatous. Stems 1–4+, ascending to erect (straight), glabrous. Leaves thin, margins usually entire, sometimes very sparsely serrulate distally, scabrous, apices acute, mucronulate, faces glabrous; basal usually deciduous at flowering (new winter rosettes developed by flowering), petiolate (petioles narrow or ± winged, then appearing sessile, slightly sheathing, ciliate), blades oblanceolate to obovate or spatulate, 5–45+ × 2–6 mm, cuneate, apices obtuse; proximal cauline usually withering by flowering, petiolate or sessile (petioles winged, slightly clasping, ciliate), blades oblanceolate or lanceolate to linear-oblanceolate or lanceolate, 40–80 (–90) × 2–5 (–6) mm, bases cuneate; distal sessile, blades linear-lanceolate to linear, ± falcate, 8–60 × 0.5–3 mm, reduced distally, bases cuneate to rounded-cuneate. Heads in paniculiform arrays, branches ascending, ± densely leafy with narrow branch leaves. Peduncles 0.2–2.8 cm, bracteate, glabrous, bracts 1–3, linear to linear-lanceolate. Involucres campanulate to cylindro-campanulate, 3.6–5 (–6) mm. Phyllaries in 4–6 series, linear-lanceolate to oblanceolate (outer) or oblong-lanceolate (inner), unequal, bases indurate 1/4–3/4 (sometimes outermost foliaceous), margins proximally narrowly scarious, erose, hyaline, distally ciliolate, green zones lanceolate, apices acute, ± spreading, involute, mucronulate, faces glabrous. Ray-florets (12–) 20–34 (–42); corollas usually white, seldom pinkish, laminae 6.8–12 × 0.7–1.8 mm. Disc-florets (30–) 40–75 (–103); corollas pale-yellow becoming pink and later brown, (2.8–) 3.1–3.9 (–4.9) mm, tubes much shorter than narrowly funnelform throats, lobes triangular, (0.3–) 0.5–0.7 (–0.8) mm. Cypselae purple to stramineous, obovoid to oblanceoloid, compressed, 1–2 mm, 4–5-nerved, faces sparsely, finely strigillose; pappi white, 1.2–3.5 mm. 2n = 16.


Phenology: Flowering late Jul–Sep.
Habitat: Lower montane
Elevation: 1800–2900 m

Discussion

Symphyotrichum porteri is the only western member of subsect. Porteriana; it grows in the foothills of the Rocky Mountains.

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

... more about "Symphyotrichum porteri"
not tailed +, rounded +  and obtuse +
distinct +
mucronulate;acute;obtuse;mucronulate;acute +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
paniculiform +
indeterminate +  and determinate +
Luc Brouillet +, John C. Semple +, Geraldine A. Allen +, Kenton L. Chambers +  and Scott D. Sundberg† +
(A. Gray) G. L. Nesom +
0.5 cm5 mm <br />0.005 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
sessile +  and petiolate +
8 cm80 mm <br />0.08 m <br /> (9 cm90 mm <br />0.09 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
4 cm40 mm <br />0.04 m <br /> (8 cm80 mm <br />0.08 m <br />) +
cuneate +  and rounded-cuneate +
indurate +
2mm;5mm +
Aster porteri +
sessile +  and petiolate +
8 cm80 mm <br />0.08 m <br /> (9 cm90 mm <br />0.09 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (6 cm60 mm <br />0.06 m <br />) +
falcate;linear-lanceolate;linear +
reduced +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
rugulose +  and muricate +
linear +  and linear-lanceolate +
barbellulate +  and barbellate +
long-rhizomatous +  and branched +
sessile +  and petiolate +
Porter’s or smooth white aster +
not 2-lipped +  and actinomorphic +
0.39 cm3.9 mm <br />0.0039 m <br /> (0.49 cm4.9 mm <br />0.0049 m <br />) +
brown +, pale-yellow becoming pink +, pinkish +  and white +
at maturity , more or less ampliate , tubes usually shorter +
0.31 cm3.1 mm <br />0.0031 m <br /> (0.39 cm3.9 mm <br />0.0039 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
purple +  and stramineous +
strigillose +  and glabrous +
compressed +, obovoid +  and oblanceoloid +
fertile +  and bisexual +
fertile +  and bisexual +
Colo. +, N.Mex. +  and Wyo. +
1800–2900 m +
strigillose +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Lower montane +
disciform +  and radiate +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
campanulate;cylindro-campanulate +
0.36 cm3.6 mm <br />0.0036 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1.8 cm18 mm <br />0.018 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
6.8mm;12mm +
2 (?) +  and 5 (?) +
0.7mm;1.8mm +
sessile +  and petiolate +
cauline +  and basal +
decurrent +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
reflexed;spreading;erect +
triangular +
serrulate +  and entire +
coarsely serrate +  and crenate or entire +
2-carpellate +
persistent +
25 +  and 40 +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
Flowering late Jul–Sep. +
linear-lanceolate +  and oblanceolate or oblong-lanceolate +
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 +
branched +  and simple +
ascending +  and erect +
1 +  and 4 +
appendaged +  and truncate +
papillate +  and smooth +
Aster ericoides var. strictus +
Symphyotrichum porteri +
Symphyotrichum sect. Symphyotrichum +
species +
funnelform-campanulate +  and cylindric +
ampliate +
10 cm100 mm <br />0.1 m <br /> (50 cm500 mm <br />0.5 m <br />) +
tree +, shrub +  and subshrub +
lanceolate +