Symphyotrichum potosinum

(A. Gray) G. L. Nesom

Phytologia 77: 289. 1995.

Common names: Santa Rita Mountain aster
Conservation concern
Basionym: Aster potosinus A. Gray Proc. Amer. Acad. Arts 15: 32. 1880
Synonyms: Aster lemmonii A. Gray
Treatment appears in FNA Volume 20. Treatment on page 480. Mentioned on page 468.

Perennials, 15–35 (–45) cm, colonial or cespitose; rhizomatous. Stems 1–3+, ascending to erect (sometimes purple or purplish brown), glabrous or glabrate, sparsely hairy in leaf-axils [villous to sericeous]. Leaves thin, apices callous-pointed, faces glabrous or glabrate; basal usually withering by flowering, long-petiolate, petioles sheathing, sparsely ciliate, blades lanceolate, 40–110 × (3–) 5–7 mm, bases attenuate, margins entire to crenulate, rarely with 1–2 teeth, apices obtuse to rounded, callus-pointed; proximalmost cauline sometimes withering by flowering, winged-petiolate or sessile distally, blades lanceolate to linear-lanceolate, 50–120 (–180) × 1–6 mm, bases attenuate, margins entire, sparsely ciliate, apices acute; distal sessile, blades subulate to lanceolate, 10–50 × 1–2 mm, bases clasping, apices acuminate. Heads (1–) 3–20 (–40), in paniculiform arrays, branches patent. Peduncles 1–4 (–6) cm, ascending, glabrate, bracts 1–4 (–5), subulate to lanceolate, foliaceous. Involucres cylindric to hemispheric, (4.5–) 5–7.3 mm. Phyllaries in 2–3 (–5) series, subulate to lanceolate, bases indurate, margins hyaline, entire to erose, often ciliate, green zones linear-lanceolate (outer) or rhombic (inner), apices acute, faces glabrous [sparsely villous]. Ray-florets 14–27; corollas white, laminae (4.6–) 5.6–7 (–9.5) –10.3 × 1.3–2 mm. Disc-florets 18–35 (–42); corollas yellow, 3.5–5 mm, tubes shorter than funnelform throats (hairy), lobes± spreading, triangular, 0.5–0.7 mm. Cypselae light-brown to gray, narrowly obovoid to fusiform, sometimes ± compressed, 2–3 mm, 5-nerved, faces glabrate to sparsely strigillose; pappi white to cream, 3.5–5.5 mm. 2n = 10.


Phenology: Flowering (Jun–)Jul–Sep.
Habitat: Moist, muddy, sandy, or rocky soils along streams
Elevation: 1500–1900 m

Discussion

Of conservation concern.

Symphyotrichum potosinum is known from Cochise County, Arizona, south into Mexico to northern Oaxaca.

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

... more about "Symphyotrichum potosinum"
not tailed +, rounded +  and obtuse +
sessile +  and winged-petiolate +
12 cm120 mm <br />0.12 m <br /> (18 cm180 mm <br />0.18 m <br />) +
distinct +
5 cm50 mm <br />0.05 m <br /> (12 cm120 mm <br />0.12 m <br />) +
subequal +
scarious +
1mm +  and 6mm +
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 +
sessile +  and winged-petiolate +
12 cm120 mm <br />0.12 m <br /> (18 cm180 mm <br />0.18 m <br />) +
5 cm50 mm <br />0.05 m <br /> (12 cm120 mm <br />0.12 m <br />) +
acute +, attenuate +, lanceolate +  and linear-lanceolate +
indurate +
1mm;6mm +
Aster potosinus +
sessile +  and winged-petiolate +
12 cm120 mm <br />0.12 m <br /> (18 cm180 mm <br />0.18 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 cm10 mm <br />0.01 m <br /> (5 cm50 mm <br />0.05 m <br />) +
subulate;lanceolate +
1mm;2mm +
rugulose +  and muricate +
subulate +  and lanceolate +
barbellulate +  and barbellate +
sessile +  and subpetiolate +
Santa Rita Mountain aster +
not 2-lipped +  and actinomorphic +
yellow +  and white +
at maturity , more or less ampliate , tubes usually shorter +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
light-brown +  and gray +
glabrate +  and strigillose +
compressed +, narrowly obovoid +  and fusiform +
fertile +  and bisexual +
fertile +  and bisexual +
Ariz. +  and Mexico +
1500–1900 m +
glabrate +  and sparsely strigillose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Moist, muddy, sandy, or rocky soils along streams +
disciform +  and radiate +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
cylindric;hemispheric +
0.5 cm5 mm <br />0.005 m <br /> (0.73 cm7.3 mm <br />0.0073 m <br />) +
0.85 cm8.5 mm <br />0.0085 m <br /> (0.95 cm9.5 mm <br />0.0095 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
5.6 (?) +  and 7 (?) +
1.3mm;2mm +
sessile +  and petiolate +
cauline +  and basal +
decurrent +
triangular +
entire +  and erose +
12 cm120 mm <br />0.12 m <br /> (18 cm180 mm <br />0.18 m <br />) +
50mm;120mm +
ciliate +  and scabrous +
acute +, attenuate +, lanceolate +  and linear-lanceolate +
1mm +  and 6mm +
2-carpellate +
white +  and cream +
persistent +
25 +  and 40 +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
Flowering (Jun–)Jul–Sep. +
subulate +  and lanceolate +
styliferous +, neuter +  and pistillate +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
exalbuminous +
Conservation concern +
branched +  and simple +
not brittle +
ascending +  and erect +
1 +  and 3 +
appendaged +  and truncate +
papillate +  and smooth +
Aster lemmonii +
Symphyotrichum potosinum +
Symphyotrichum subg. Astropolium +
species +
ampliate +
35 cm350 mm <br />0.35 m <br /> (45 cm450 mm <br />0.45 m <br />) +
cespitose +  and colonial +
15 cm150 mm <br />0.15 m <br /> (35 cm350 mm <br />0.35 m <br />) +
tree +, shrub +  and subshrub +
rhombic +  and linear-lanceolate +