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Alexander's Rock aster

southern swamp aster

Habit Plants 30–50(–80) cm; in clumps, eglandular; rhizomes short, creeping, ± woody in age. Plants 20–80 cm; in clumps and clones, eglandular; rhizomes creeping, herbaceous and thin, becoming thick and woody, scaly.
Stems

1–5+, erect to ascending, simple, strict, slender, stiff, proximally glabrous or glabrate, distally hirtello-puberulent.

1–10+, erect, often reddish, simple, straight (brittle), proximally glabrous, glabrescent, or sparsely strigillose, distally strigillose or ± villoso-hirsute (at least in arrays).

Leaves

basal and cauline, firm, blades (1-nerved) linear to lance-linear or oblong-linear (grasslike), 25–140+ × 2–5 mm, ± coriaceous, bases sheathing, margins entire to remotely serrulate-spinose, indurate, remotely scabrous, spines thickened, apices acute, revolute, faces glabrous;

basal and proximal cauline often withering by flowering, bases marcescent, ± long-petiolate;

mid and distal progressively sessile and reduced.

basal and cauline, firm, only midnerves evident, margins indurate, entire or sometimes remotely spinulose-serrate, scabrous, spines indurate, ± pronounced, apices mucronate or indurate, abaxial faces glabrous or scabrous, adaxial sparsely hirtellous, distal often more hairy;

basal and proximalmost cauline withering by flowering, petioles (often marcescent, to 20 mm), bases sheathing, blades elliptic to lanceolate (basal) or linear-lanceolate, ± arcuate (proximal), 15–103 × 5–9 mm, bases cuneate, apices obtuse (basal) to acute;

cauline progressively sessile (petioles more winged) and reduced, blades lanceolate or linear-lanceolate to linear, ± arcuate, 18–132+ × 2–6 mm, margins sometimes revolute, apices acute.

Peduncles

densely hirtellous;

bracts 1–2, usually immediately subtending heads.

ascending, usually mostly 1–10+ cm (seldom not elongating, sometimes those of young heads appearing short or absent), thin, hirtello-puberulent to villoso-hirsute;

bracts 2–5, often 1–2 subtending heads, sometimes phyllary-like (bases pale, indurate).

Involucres

cylindro-campanulate, 7–9 mm, shorter than pappi.

campanulate, 9–11 mm, much shorter than pappi.

Ray florets

8–20;

corollas bluish white to lavender or deep violet, 5–10 × 1–1.7 mm.

15–35;

corollas deep lavender to purple, (10–)15–20 × 1–2.3 mm.

Disc florets

15–45;

corollas yellow, 5.5–7 mm, barely ampliate, tubes shorter than narrowly funnelform throats, lobes erect, triangular, 0.6–0.7 mm.

25–60;

corollas yellow, 5.5–7 mm, slightly ampliate, tubes much shorter than cylindro-funnelform throats, lobes spreading, lanceolate-acuminate, 0.75–1.1 mm.

Phyllaries

30–55+ in 4–5 series, unequal, chartaceous, bases indurate, margins narrowly hyaline, scabrous, erose, fimbriate, apices appressed or reflexed, acute, sometimes acuminate (some outer), mucronate, marginally thickened, faces glabrous;

outer lance-oblong, rounded, apical zones dark green, flat;

inner linear-oblong, apical zones pale green, restricted to broadly acute tips.

40–65+ in 4–5 series, lanceolate or oblong (outer) to linear-oblanceolate or linear (inner), unequal, membranous, bases indurate, rounded (particularly outer), green zones well defined, slightly expanded in distal 1/3–2/3 (foliaceous), reaching margins (outer wholly foliaceous, outermost are bracts subtending heads) to 1/6 or less and not reaching margins or none (inner), margins sometimes distally purplish (particularly inner), indurate, narrowly scarious, erose proximally to nearly completely so (inner), densely ciliate proximally (scarious part) to distally scabrous (foliaceous part), apices loose and often spreading, sometimes squarrose, obtuse to sometimes acute, mucronate, faces sparsely to densely strigillose.

Heads

3–15+ in narrow, flat-topped corymbiform arrays.

(1–)4–10+ in open, corymbiform arrays, seldom borne singly, with ascending branches.

Cypselae

tan, fusiform, ± compressed, ca. 5 mm, ribs 7–10(–12) (stramineous, broad), strigillose;

pappi of cinnamon to sordid bristles 5.5–6 mm, equaling disc corollas.

stramineous to tawny, cylindric to narrowly obovoid, slightly compressed, 2.3–3.6 mm, ribs 10–16, sparsely strigillose;

pappi of stramineous (firm, sometimes apically clavellate) bristles 5–6.7 mm, ± equaling disc corollas.

2n

= 18.

= 36.

Eurybia avita

Eurybia paludosa

Phenology Flowering late summer–early fall. Flowering late summer–fall.
Habitat Shallow sandy soils around edges of granite flatrock outcrops Moist savannas, margins of pools and swamps, low pinelands, seldom on sand hills of coastal plains, open hammocks
Elevation 100–500 m (300–1600 ft) 0–100 m (0–300 ft)
Distribution
from FNA
GA; NC; SC
[BONAP county map]
from FNA
FL; GA; NC; SC
[WildflowerSearch map]
[BONAP county map]
Discussion

Of conservation concern.

Eurybia avita is known from Stone Mountain (the type location, where it is now extirpated according to R. Kral 1983, vol. 2) and granite flatrocks in Georgia, and from Pickens County in South Carolina, where it is imperiled; it is presumed extirpated from North Carolina (www.natureserve.org). Kral mapped the species; he underlined its similarities to both E. surculosa and E. paludosa and the need for further studies of its relationships.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Eurybia paludosa is often confused with E. hemispherica, with which it is closely related. It is present on the Atlantic coastal plain from North Carolina to northeastern Florida. The two species are disjunct geographically and ecologically, even when they occur in the same states. In North Carolina, for instance, E. paludosa is coastal while E. hemispherica is found in the mountains. In northern Florida, the former is found only in Nassau County, while the latter is present only in the western panhandle. Their ranges do not overlap.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 20, p. 378. FNA vol. 20, p. 380.
Parent taxa Asteraceae > tribe Astereae > Eurybia Asteraceae > tribe Astereae > Eurybia
Sibling taxa
E. chlorolepis, E. compacta, E. conspicua, E. divaricata, E. eryngiifolia, E. furcata, E. hemispherica, E. integrifolia, E. jonesiae, E. macrophylla, E. merita, E. mirabilis, E. paludosa, E. radula, E. radulina, E. saxicastelli, E. schreberi, E. sibirica, E. spectabilis, E. spinulosa, E. surculosa, E. ×herveyi
E. avita, E. chlorolepis, E. compacta, E. conspicua, E. divaricata, E. eryngiifolia, E. furcata, E. hemispherica, E. integrifolia, E. jonesiae, E. macrophylla, E. merita, E. mirabilis, E. radula, E. radulina, E. saxicastelli, E. schreberi, E. sibirica, E. spectabilis, E. spinulosa, E. surculosa, E. ×herveyi
Synonyms Aster avitus Aster paludosus, Heleastrum paludosum
Name authority (Alexander) G. L. Nesom: Phytologia 77: 259. (1995) (Aiton) G. L. Nesom: Phytologia 77: 261. (1995)
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