Eurybia surculosa |
Eurybia |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
creeping aster |
aster |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Habit | Plants 10–90 cm; in clones and clumps (sometimes with rosettes), eglandular (except pedicels); rhizomes slender, herbaceous becoming woody, scaly. | Perennials, 10–120 cm (rhizomes long and slender to short and thick, sometimes cormoid, often becoming woody). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stems | 1–3+, erect, simple, straight, proximally sparsely strigillose to glabrescent, distally strigose or villoso- or hirsuto-strigose. |
ascending to erect, usually simple, rarely branched proximally, glabrous or ± densely hairy, usually eglandular, sometimes stipitate-glandular. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leaves | basal and cauline, firm (only midnerves conspicuous), margins slightly revolute, slightly indurate, entire or sometimes remotely crenulate-serrulate, scabrous, teeth indurate, apices acute to obtuse, indurate, often mucronate, abaxial faces scabrous, adaxial sparsely strigose or glabrous; basal and proximal cauline usually persistent, sometimes withering by flowering (bases often marcescent), petioles sometimes narrowly winged, bases sheathing, blades narrowly elliptic, narrowly ovate, or lanceolate to spatulate, narrowly obovate, or oblanceolate, 13–135 × (2–)6–35 mm (earliest smaller), bases attenuate to cuneate; mid short-winged-petiolate or sessile, blades lance-oblong, lance-elliptic, lanceolate, or oblanceolate, 22–105 × 3–14 mm, gradually reduced distally, bases slightly auriculate-clasping to cuneate or attenuate; distal (arrays) sessile, blades lanceolate to linear, 7–42 × 1–6 mm, abruptly reduced. |
basal and cauline; alternate; sessile or petiolate; blades cordate, ovate, obovate, elliptic, or oblong to spatulate, oblanceolate, or lanceolate, usually gradually reduced distally, margins entire or serrate, sometimes spinulose-serrate, faces glabrate to hairy, usually eglandular, sometimes stipitate-glandular. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Peduncles | densely strigose or strigoso-hispid, sometimes sparsely long-stipitate-glandular distally; bracts (0–)1–3(–6), leaflike to phyllary-like (bases indurate), scabrous or sparsely strigose. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Involucres | cylindro-campanulate, 7–11(–13) mm, shorter than pappi. |
cylindro-campanulate to broadly campanulate, (4–14(–16) ×) 4–25+ mm. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Receptacles | flat to slightly convex, pitted, epaleate. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ray florets | 13–30; corollas bluish violet, (8–)11.5–15.5 × 1.5–2.3 mm. |
5–60, pistillate, fertile; corollas white to purple (coiling at maturity). |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Disc florets | 25–40; corollas pale yellow turning purplish, 5–7.2 mm, slightly ampliate, tubes shorter than funnelform throats, lobes erect, deltate to triangular, 0.75–1.1 mm. |
8–260, bisexual, fertile; corollas yellow, becoming purple at maturity, barely to abruptly ampliate, tubes shorter to longer than funnelform to campanulate throats, lobes 5, usually erect to spreading, sometimes ± reflexed, deltate, triangular, or lanceolate; style-branch appendages lanceolate. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Phyllaries | 35–65 in 4–5 series, oblong (outer) to linear-oblong or seldom linear (inner), strongly unequal, membranous, bases indurate, rounded (outer), dark green zones foliaceous, sometimes slightly dilated, in distal 1/3–1/2 (outer) to 1/8–1/7 or none and not reaching margins (inner), margins hyaline or sometimes purplish, narrowly scarious, erose, ciliate (scarious parts), ± scabrous (foliaceous parts), sometimes short-stipitate-glandular (innermost), apices spreading to squarrose, obtuse, often dilated (innermost), mucronulate (outer) or apiculate (inner), abaxial faces glabrous or strigillose, both scabrellous on foliaceous parts. |
20–140 in 3–7 series, 1-nerved (usually rounded adaxially, sometimes low-keeled), broadly ovate or oblong to oblanceolate, lanceolate, or linear, unequal, bases indurate (rarely wholly foliaceous), margins narrowly scarious (seldom herbaceous), often ciliolate (green zones ± basally truncate), in distal 1/3–3/4 of phyllary (outer) to less than 1/6 and only along midnerves (inner), apices obtuse to acute, faces glabrous, ± strigillose, puberulent, scabrellous, strigoso-villous, or villous, sometimes ± stipitate-glandular. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Heads | (1–)3–50(–122+), usually in open or dense, corymbiform arrays, seldom borne singly. |
radiate, usually in corymbiform arrays, rarely borne singly. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Cypselae | brown, cylindro-obconic, slightly compressed, 3.2–3.5 mm, ribs 8–10, stramineous, strigillose; pappi of tawny-yellowish to pinkish bristles 5.2–7.1 mm, ± equaling disc corollas. |
cylindro-obconic to fusiform, ± compressed, 7–12(–18)-nerved, faces glabrous or sparsely to densely strigillose, eglandular; pappi persistent, of 35–70+, reddish, orange, cinnamon, tawny, tan, yellowish, or pinkish, unequal, soft to stiff, barbellate or barbellulate, often apically ± clavate bristles in 2–4 series. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
x | = 9. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
2n | = 36. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Eurybia surculosa |
Eurybia |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Phenology | Flowering summer–fall. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Habitat | Dry to wet, especially sandy soils, open, pinelands, oak-scrub, clearings, bogs, roadsides | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Elevation | 200–1500 m (700–4900 ft) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Distribution |
AL; CT; DE; GA; KY; MA; MD; NC; OH; SC; TN; VA
|
North America; n Eurasia |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Discussion | Eurybia surculosa is of conservation concern in Virginia and Alabama. It is often confused with E. compacta, its close relative from the coastal plains. In states where both are present, it is found only inland in the southern Appalachian Mountains and not on the coastal plains; its larger heads help to differentiate it from E. compacta. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 23 (23, including 1 hybrid, in the flora). Eurybia traditionally has been treated within Aster in a broad sense. G. L. Nesom (1994b), in his review of North American asters, showed that Aster in a broad sense does not form a natural group and proposed splitting it into several genera, among which Eurybia is one. In his treatment, Nesom included Herrickia within Eurybia, as sect. Herrickia in subg. Eurybia. Such views were generally supported in molecular phylogenetic studies (J. C. Semple et al. 2002). L. Brouillet et al. (2004) showed, however, that Oreostemma, Herrickia, Eurybia, and Triniteurybia form a grade at the base of the Machaerantherinae and that Herrickia and Eurybia are distinct. The subgenera and sections proposed by G. L. Nesom (1994b), based on anterior taxonomy, could not be confirmed in the molecular studies cited above. I chose not to use subgeneric limits as proposed by Nesom because they may not reflect actual relationships. For instance, there is a clear gradation between members of sect. Calliastrum (Torrey & A. Gray) G. L. Nesom (subg. Eurybia) and sect. Heleastrum (de Candolle) G. L. Nesom. Also, I do not recognize sect. Eryngiifoliae (Alexander) G. L. Nesom distinct from sect. Heleastrum, as there is no clear demarcation between the two as currently defined. Finally, sect. Radulini (Rydberg) G. L. Nesom appears artificial to me, but currently there is no good way to reassign its species. The Eurybia radulina complex of western North America clearly constitute a group, but it is unclear whether the western E. conspicua or the eastern E. radula and E. saxicastelli are close to them. Members of other sections may have played a role in the reticulate evolution of sect. Eurybia, even though it is well marked by its cordate leaves and disc florets with long tubes and short, campanulate corollas. Therefore, species are described below in a rough taxonomic order, with diploids listed before polyploids of the same group. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Key |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Source | FNA vol. 20, p. 377. | FNA vol. 20, p. 365. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Synonyms | Aster surculosus | Aster subg. E. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Name authority | (Michaux) G. L. Nesom: Phytologia 77: 262. (1995) | (Cassini) Cassini: in F. Cuvier, Dict. Sci. Nat. ed. 2, 16: 46. (1820) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Web links |