Symphyotrichum potosinum |
Symphyotrichum novae-angliae |
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Santa Rita Mountain aster |
aster de nouvelle-angleterre, New England American-aster, New England aster, New England or michaelmas daisy |
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Habit | Perennials, 15–35(–45) cm, colonial or cespitose; rhizoma-tous. | Perennials, 30–120 cm, cespitose; with thick, woody, branched caudices, or short, fleshy rhizomes, sometimes with woody cormoid portions. |
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 (stout, light to dark brown, sometimes purplish distally), proximally sparsely to moderately hispiduloso-hirsute or pilose, distally moderately to densely so, stipitate-glandular. |
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. |
(light to dark green) thin, often stiff, margins entire or sometimes with shallow teeth, ciliate; basal withered or withering by flowering, sessile, blades (3-nerved) usually spatulate, sometimes oblanceolate, 20–60 × 5–15 mm, bases attenuate, apices acute, faces sparsely hirsute; proximal cauline withering by flowering, sessile, blades oblong or lanceolate, 50–100 × 5–15(–20) mm, bases auriculate-clasping, margins entire, pustulate-scabrous, apices acute, mucronulate, faces stipitate-glandular, abaxial thinly strigose, adaxial hirsute or hispidulous; distal sessile, blades oblanceolate, 30–80 × 6–15 mm, gradually reduced distally, bases auriculate-clasping, apices acute to obtuse, mucronate to minutely white-spinulose, faces moderately to densely short-soft-hairy, sparsely to moderately stipitate-glandular. |
Peduncles | 1–4(–6) cm, ascending, glabrate, bracts 1–4(–5), subulate to lanceolate, foliaceous. |
dilated distally, 0.3–4 cm, densely short-hairy, stipitate-glandular, bracts 1–4, foliaceous, linear to narrowly lanceolate, densely short-hairy, stipitate-glandular, grading into phyllaries. |
Involucres | cylindric to hemispheric, (4.5–)5–7.3 mm. |
campanulate to hemispheric, (5–)7–9(–15) mm. |
Ray florets | 14–27; corollas white, laminae (4.6–)5.6–7(–9.5)–10.3 × 1.3–2 mm. |
(40–)50–75(-100); corollas dark rose to deep purple (pale pink or white), laminae 9–13 × 0.8–1.3 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. |
50–110; corollas light yellow becoming purple, (4–)4.5–5.5(–7) mm, tubes ± 1/2 narrowly funnelform throats (glabrous or thinly puberulent), lobes triangular, 0.4–0.7 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]. |
in 3–5(–6) series (dark green to purple-tinged), linear-lanceolate, subequal, outer foliaceous, mid and inner scarious in basal 1/3–1/2, margins stipitate-glandular, apices long-acuminate to acuminate, spreading to reflexed or squarrose, faces glabrous, outer densely stipitate-glandular. |
Heads | (1–)3–20(–40), in paniculiform arrays, branches patent. |
in leafy, often crowded, paniculo-corymbiform arrays. |
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, oblong or obconic, not compressed, 1.8–2.5(–3) × 0.6–1 mm, 7–10-nerved, faces densely sericeous, sparsely stipitate-glandular; pappi tawny (barb tips sometimes rose-tinged), 4.5–6 mm. |
2n | = 10. |
= 10. |
Symphyotrichum potosinum |
Symphyotrichum novae-angliae |
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Phenology | Flowering (Jun–)Jul–Sep. | Flowering Aug–Oct(–Nov). |
Habitat | Moist, muddy, sandy, or rocky soils along streams | Open, moist to wet, sandy or loamy, rich soils, fields, prairies, meadows, marshy grounds, shrubby swamps, fens, shores, thickets, moist edges of woods, roadsides, railroad rights-of-way, somewhat weedy |
Elevation | 1500–1900 m (4900–6200 ft) | 0–1600 m (0–5200 ft) |
Distribution |
AZ; Mexico |
AL; AR; CO; CT; DC; DE; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; SD; TN; UT; VA; WA; WI; WV; WY; MB; NB; NS; ON; QC [Introduced in Europe]
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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.) |
Symphyotrichum novae-angliae is escaped from cultivation and introduced in Montana, Oregon, Utah, Washington, and Wyoming, and has been reported as an ephemeral escape in British Columbia. It possibly escaped from cultivation elsewhere. The Michaelmas daisy is widely sold in the horticultural trade, where cultivars have been developed. Forms have been described that correspond to color genetic variants within natural populations {Aster novae-angliae forma roseus (Desfontaines) Britton; A. novae-angliae forma geneseensis House}; they are not recognized here. Symphyotrichum novae-angliae resembles Canadanthus modestus, but the ranges of the two do not overlap, and the latter has sparsely hairy cypselae with dark ribs. Symphyotrichum novae-angliae hybridizes with S. ericoides, forming the F1 intersectional hybrid S. ×amethystinum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 480. | FNA vol. 20, p. 487. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Aster potosinus, Aster lemmonii | Aster novae-angliae, Virgulus novae-angliae |
Name authority | (A. Gray) G. L. Nesom: Phytologia 77: 289. (1995) | (Linnaeus) G. L. Nesom: Phytologia 77: 287. (1995) |
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