Symphyotrichum ericoides |
Symphyotrichum rhiannon |
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aster éricoïde, heath American-aster, heath-leaf aster, little gray aster, rayless alkali aster, tuft white prairie aster, white heath aster |
Rhiannon aster, Rhiannon's aster |
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Habit | Perennials, 20–80(–100) cm, colonial or cespitose, eglandular; branched rhizomatous, or with ± cormoid, branched, woody caudices. | Perennials, 15–40(–60) cm, colonial; thinly long-rhizomatous. | ||||
Stems | 1–3+, ascending to erect (grayish brown to brown), sparsely to densely hispido-strigose, sometimes glabrescent proximally. |
1, erect (straight), hirsute to hispido-hirsute, hirsutulous distally. |
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Leaves | usually all except rameal withered by flowering, (light grayish green) firm apices ± white-spine-tipped (often with clusters of smaller leaves in axils); basal sessile, blades (3-nerved) oblanceolate to oblong or spatulate, 10–50 × 10–25 mm, bases attenuate, margins usually entire, rarely remotely serrate, scabrous, apices rounded to obtuse, faces usually sparsely hairy, often glabrous; proximal cauline sessile, blades (1- or 3-nerved) linear to lanceolate or oblong, 10–40(–60) × 1.5–4(–7) mm, reduced distally, bases cuneate, coarsely ciliate, margins entire, coarsely ciliate, apices acute or obtuse, faces moderately to densely strigose or hirsute; distal sessile, blades oblong-ovate, 10–40 × 1.5–3.5 mm, abruptly reduced distally, bases cuneate, margins entire, apices acute, faces moderately to densely strigose. |
margins shallowly crenate to serrate-crenate, abaxial faces strigillose, adaxial scabrous; basal withering by flowering, petiolate, petioles winged, clasping to subclasping, shallowly auriculate, blades subspatulate or oblanceolate-elliptic, 30–70 × 10–15 mm, bases attenuate to cuneate, apices acute; proximal cauline withering by flowering, widely winged-petiolate, blades oblanceolate-elliptic, 50–110 × 8–22 mm, bases attenuate, apices acute; distal subsessile, blades oblong-lanceolate, 10–30 × 4–6(–8) mm. |
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Peduncles | 0.5–1(–2) cm or subsessile, densely hairy, bracts dense, linear to narrowly lanceolate, usually reflexed, sometime appressed to ascending, 1.5–5(–6) mm, densely hairy, grading into phyllaries. |
0.5–1.5(–3) cm, bracts foliaceous. |
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Involucres | cylindric to campanulate, 2.5–4.5(–5) mm. |
turbino-campanulate, 6–11 wide mm. |
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Ray florets | (8–)10–18(–20); corollas usually white, rarely pink or bluish, laminae 6–12(–20) × 0.7–1.2 mm. |
18–32; corollas blue to lavender, laminae 6–9 × 0.8–1.4 mm. |
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Disc florets | 6–12(–20); corollas yellow becoming brown, 2.5–4 mm, throats narrowly funnelform, lobes triangular, 0.5–0.6 mm, glabrous. |
[number unknown]; corollas yellow, at least lobes becoming purple, (4–)4.5–5.5 mm, tubes shorter than cylindro-funnelform limbs, lobes triangular, 0.8–1 mm. |
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Phyllaries | in 3–4 series, oblanceolate to ± spatulate, unequal, firm, bases (whitish to tan) ± indurate in proximal 1/2–2/3, margins hyaline, scabrous proximally, green zones diamond-shaped, in distal 1/2, apices spine-tipped, (outer) spreading to reflexed or squarrose, faces (outer) sparsely to densely hispid, scabroso-hirsute adaxially, (inner) glabrous. |
in 3–4 series, slightly unequal, narrowly oblong-lanceolate, bases indurate 1/2–2/3, margins not scarious, irregularly ciliolate, green zones rhombic-lanceolate, apices acute to acuminate, faces glabrous or distally strigoso-puberulent. |
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Heads | (1–200+) in paniculiform arrays, branches fastigiate or arrays often pyramidal, racemiform, secund, crowded. |
in broad, cylindro-paniculiform arrays, branches ascending. |
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Cypselae | deep purple turning brown, obovoid to oblong-obovoid, ± falcate, not compressed, 1.2–2 × 0.4–0.6 mm, 7–9-nerved (faint), faces sericeous or densely strigillose; pappi whitish, 3–4 mm. |
tan to often purplish, oblong to oblanceoloid, ± compressed, 2.6–3 mm, 4–6-nerved, faces sparsely strigillose; pappi white, [length unknown] mm. |
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Symphyotrichum ericoides |
Symphyotrichum rhiannon |
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Phenology | Flowering Sep–Oct(–Nov). | |||||
Habitat | Ultramafic outcrop barrens, in Quercus alba-Pinus rigida-Sporobolus heterolepis-Andropogon gerardii woodlands and grass-dominated areas | |||||
Elevation | 900–1300 m (3000–4300 ft) | |||||
Distribution |
AR; AZ; CO; CT; DC; DE; IA; ID; IL; IN; KS; MA; MD; ME; MI; MN; MO; MS; MT; ND; NE; NJ; NM; NY; OH; OK; OR; PA; RI; SD; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NT; ON; QC; SK; n Mexico
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NC |
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Discussion | Varieties 2 (2 in the flora). Symphyotrichum ericoides resembles S. pilosum var. pilosum, which has larger heads, longer rays, and phyllaries that are not spine-tipped, though the revolute margins can make them appear so. Two subspecies and four weakly separated varieties of S. ericoides were recognized by A. G. Jones (1978). Tetraploids of var. ericoides on the eastern prairies can be difficult to distinguish from S. falcatum. A number of aster cultivars are sold under the name “Aster ericoides.” These are all derived from European garden plants and are either cultivars of S. dumosum, S. lateriflorum, S. pilosum, or S. racemosum, or hybrids involving one of those species and another taxon. The misapplication of the epithet ericoides dates back to the nineteenth century and has persisted in the horticultural literature. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Symphyotrichum rhiannon is known only from a southern Appalachian high-elevation outcrop barren around Buck Creek, southern Nantahala Mountains, Clay County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 494. | FNA vol. 20, p. 526. | ||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Aster ericoides, Lasallea ericoides, Virgulus ericoides | |||||
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 280. (1995) | Weakley & Govus: Sida 21: 828, fig. 1. (2004) | ||||
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