Symphyotrichum potosinum |
Symphyotrichum drummondii |
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Santa Rita Mountain aster |
Drummond's aster |
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Habit | Perennials, 15–35(–45) cm, colonial or cespitose; rhizoma-tous. | Perennials, 30–120 cm, cespitose; short-rhizomatous or with stout, often woody caudices. | ||||
Stems | 1–3+, ascending to erect (sometimes purple or purplish brown), glabrous or glabrate, sparsely hairy in leaf axils [villous to sericeous]. |
1–5+, erect (straight, stout), glabrate or glabrescent, sparsely pilose, or hirsuto-pilose proximally, ± densely so distally. |
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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. |
(abaxially pale or grayish green, adaxially dark green) initially ± firm or membranous, becoming thicker, margins crenate-serrate to serrate, strigoso-ciliate to scabrous, apices acuminate to acute, mucronate, abaxial faces scabrous to densely piloso-strigose, more so on veins, adaxial scabrous to glabrate; basal withering by flowering, long-petiolate (petioles narrowly winged, sheathing, sometimes ciliate), blades ovate to ovate-oblong or -lanceolate to elliptic or suborbiculate, 10–85(–100) × 8–60 mm, bases deeply cordate to rounded or abruptly attenuate, margins crenate-serrate, apices usually rounded to obtuse, rarely acute; proximal cauline often withering by flowering, long-petiolate (petioles narrowly winged, more broadly so distally, ciliate), blades ovate or ovate-lanceolate, (25–)50–120(–150) × (15–)20–50(–65) mm, progressively to slightly reduced distally, bases deeply to shallowly cordate or rounded, margins crenate-serrate to sharply serrate; distal petiolate or subpetiolate or sessile, petioles broadly winged, blades ovate to ovate- or oblong-lanceolate, to oblong-elliptic or linear-lanceolate (4–)5–110 × 1–50 mm, reduced distally (sharply so on array branches in var. texanum), bases shallowly cordate or rounded to attenuate or cuneate (distally), margins crenate-serrate or -serrulate or entire. |
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Peduncles | 1–4(–6) cm, ascending, glabrate, bracts 1–4(–5), subulate to lanceolate, foliaceous. |
0, or 0.2–1.5(–4) cm, densely ascending- or appressed-bracteate, pilosulous, bracts 4–17+, lanceolate or subulate to linear-oblanceolate, distally grading into phyllaries, pilosulous or strigoso-ciliate. |
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Involucres | cylindric to hemispheric, (4.5–)5–7.3 mm. |
campanulate, (3.5–)4.5–6(–6.5) mm. |
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Ray florets | 14–27; corollas white, laminae (4.6–)5.6–7(–9.5)–10.3 × 1.3–2 mm. |
(8–)10–15(—20); corollas usually bright blue to purple or lavender, sometimes white, laminae (5–)7–10(–12) × 1–1.8 mm. |
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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. |
(10–)13–15(–22); corollas cream to yellow, becoming deep purple or reddish purple, 3.5–4.5(–5) mm, tubes shorter than funnelform to cylindric throats, lobes triangular to lanceolate, 0.4–0.7 mm. |
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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]. |
in 4–5 series, subulate or lanceolate (outermost) to narrowly oblong-lanceolate, unequal, bases indurate 1/4–3/4, margins narrowly scarious proximally, hyaline, ciliate, bodies sometimes green to margins distally, green zones lanceolate to linear-lanceolate, apices acute to acuminate or long-acuminate, tips often purple, sometimes involute, mucronulate, faces glabrous. |
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Heads | (1–)3–20(–40), in paniculiform arrays, branches patent. |
in open, paniculiform arrays, branches ascending to divaricate, often densely racemiform or ± paniculiform (lateral ones open, racemiform) to subsecund, ± stiff to lax, long to relatively short, ± closely to ± remotely leafy, branch leaves progressively or ± abruptly reduced distally. |
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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. |
dull purple or brown to tan (ribs tan to stramineous), obovoid, ± compressed, (1.5–)2–3 mm, 5–6-nerved, faces glabrate to sparsely strigillose distally; pappi cream to rose-tinged, 3–4 mm. |
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2n | = 10. |
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Symphyotrichum potosinum |
Symphyotrichum drummondii |
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Phenology | Flowering (Jun–)Jul–Sep. | |||||
Habitat | Moist, muddy, sandy, or rocky soils along streams | |||||
Elevation | 1500–1900 m (4900–6200 ft) | |||||
Distribution |
AZ; Mexico |
AL; AR; GA; IA; IL; IN; KS; KY; LA; MD; MI; MN; MO; MS; NE; OH; OK; PA; TN; TX; WI; WV; ne Mexico
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Discussion | Of conservation concern. Symphyotrichum potosinum is known from Cochise County, Arizona, south into Mexico to northern Oaxaca. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). Variety texanum is tetraploid; var. drummondii is both diploid and tetraploid. The tetraploid race of var. drummondii is most likely autopolyploid; origin of var. texanum has not been determined. The two taxa intergrade and do not appear to warrant species status. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 480. | FNA vol. 20, p. 503. | ||||
Parent taxa | ||||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Aster potosinus, Aster lemmonii | Aster drummondii, Aster sagittifolius var. drummondii | ||||
Name authority | (A. Gray) G. L. Nesom: Phytologia 77: 289. (1995) | (Lindley) G. L. Nesom: Phytologia 77: 279. (1995) | ||||
Web links |