Oclemena acuminata

(Michaux) Greene

Leafl. Bot. Observ. Crit. 1: 4. 1903.

Common names: Whorled wood aster aster acuminé
IllustratedEndemic
Basionym: Aster acuminatus Michaux Fl. Bor.-Amer. 2: 109. 1803
Synonyms: Aster acuminatus var. magdalenensis Fernald
Treatment appears in FNA Volume 20. Treatment on page 79. Mentioned on page 81.

Plants (2–) 10–80 (–100) cm (in extensive, lax clones; rhizomes superficial, elongate, herbaceous or woody, simple). Stems 1, erect, stout (2–4 mm diam.), flexuous, simple, ± densely villosulous, eglandular. Leaves 11–18, sometimes ± crowded distally (often seemingly whorled), proximal often withering by flowering; sessile or winged-subpetiolate; blades obovate to oblanceolate, (20–) 60–150 (–170) × (2–) 10–45 (–50) mm, bases cuneate to attenuate, margins flat, serrate distally, teeth sharp, acuminate, ciliate, apices acuminate, faces sparsely villosulous (abaxial mostly along veins and very sparsely stipitate-glandular; array leaves reduced distally). Heads (1–) 5–46 (–61+) in open corymbiform arrays, branches arching-ascending, at nearly right to ± acute angles with stems. Peduncles thin, 0.9–4.5 cm, densely villosulous, eglandular; bracts 1–2, linear, sparsely villosulous. Involucres 5–10 mm. Phyllaries linear-lanceolate to linear, sparsely villosulous or glabrous, sparsely gland-dotted. Ray-florets (9–) 15 (–18); corollas white, seldom pinkish, 15–20 × 1.4–2 mm. Disc-florets 14–30; corollas ampliate, 5.5–7.5 mm, sparsely glandular; tubes shorter than narrowly campanulate, sparsely strigillose throats, lobes reflexed, 0.5–1 mm. Cypselae tan, fusiform-obconic, ± compressed, 2.8–3.6 mm, ribs 3–5 (concolorous with bodies), faces glabrous, gland-dotted; pappi of whitish bristles in 3 series, outer shorter than disc corollas (innermost attenuate). 2n = 18.


Phenology: Flowering late summer–early fall.
Habitat: Cool, mesic to humid forests with usually well-drained, often acidic soils, from red spruce-Fraser fir Appalachian forests (south) to hemlock-white pine-northern hardwoods or Acadian forests, aspen-white birch groves or southern-exposed, open fir forests (north), sometimes clearings and forest edges, ridges
Elevation: 0–2000 m

Distribution

V20-152-distribution-map.gif

N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Conn., Ga., Ky., Maine, Md., Mass., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va.

Discussion

Oclemena acuminata is an Appalachian element. It may be extirpated from Ohio. L. Brouillet and J.-P. Simon (1981) discussed its distribution and ecology. It is adapted to mesic forest environments with relatively low light levels, with mid leaves larger or leaves pseudoverticillate to maximize light capture while minimizing self-shading. Such pseudoverticillate phenotypes have been called A. acuminatus forma subverticillatus Fernald; they are not recognized here (forma acuminatus has regularly dispersed leaves). When growing in exposed habitats, at forest edges, in clearings, or on ridges, O. acuminata is often chlorotic and reduced in size. Hypothesized introgression from O. nemoralis in the southern Appalachians (L. M. Hill 1976), far to the south of the latter’s range, based on morphologic and chemical data, appears unlikely and may represent misinterpretation of such chlorotic individuals. The species has been the object of autecologic studies (Brouillet and Simon 1979, 1980; L. F. Pitelka et al. 1980, 1983, 1985; A. A. Winn and Pitelka 1981; J. W. Ashmun et al. 1985; Pitelka and W. F. Curtis 1986). Aster acuminatus forma discoideus Kuntze, forma subdiscoideus Kuntze, and forma virescens Victorin & J. Rousseau apply to sterile phenotypes in which florets are replaced by bracts; forms are not recognized here.

Selected References

None.

Lower Taxa

None.

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... more about "Oclemena acuminata"
stipitate-glandular +, puberulent +  and glabrous +
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
corymbiform +  and open +
indeterminate +  and determinate +
Luc Brouillet +
(Michaux) Greene +
cuneate +  and attenuate +
not indurate +
Aster acuminatus +
compound +  and simple +
15 cm150 mm <br />0.15 m <br /> (17 cm170 mm <br />0.17 m <br />) +
4.5 cm45 mm <br />0.045 m <br /> (5 cm50 mm <br />0.05 m <br />) +
6 cm60 mm <br />0.06 m <br /> (15 cm150 mm <br />0.15 m <br />) +
mid +  and proximal +
obovate;oblanceolate +
reduced +  and largest +
10mm;45mm +
rugulose +  and muricate +
villosulous +
arching-ascending +
? (?) +  and ? (?) +
Whorled wood aster +  and aster acuminé +
not 2-lipped +  and actinomorphic +
pinkish +  and white +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
ampliate +
shorter to longer +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
compressed +  and fusiform-obconic +
fertile +  and bisexual +
fertile +  and bisexual +
N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, P.E.I. +, Que. +, Conn. +, Ga. +, Ky. +, Maine +, Md. +, Mass. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, R.I. +, Tenn. +, Vt. +, Va. +  and W.Va. +
0–2000 m +
gland-dotted +
glabrous +  and villosulous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Cool, mesic to humid forests with usually Cool, mesic to humid forests with usually well-drained, often acidic soils, from red spruce-Fraser fir Appalachian forests (south) to hemlock-white pine-northern hardwoods or Acadian forests, aspen-white birch groves or southern-exposed, open fir forests (north), sometimes clearings and forest edges, ridgesmetimes clearings and forest edges, ridges +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
cylindro-campanulate +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
short-petiolate +  and sessile +
11 (?) +  and 18 (?) +
triangular +  and lanceolate +
2-carpellate +
persistent +
0.9 cm9 mm <br />0.009 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
Flowering late summer–early fall. +
glabrous +  and villosulous +
linear-lanceolate +  and linear +
winged-subpetiolate +  and sessile +
Leafl. Bot. Observ. Crit. +
bearing subulate enations +, hairy +  and bristly +
planoconvex +
3 +  and 5 +
fleshy +  and fibrous +
exalbuminous +
Illustrated +  and Endemic +
eglandular +  and simple +
flexuous +
appendaged +  and truncate +
papillate +  and smooth +
Aster acuminatus var. magdalenensis +
Oclemena acuminata +
Oclemena +
species +
strigillose +
campanulate +
acuminate +  and sharp +
ampliate +
90 cm900 mm <br />0.9 m <br /> (100 cm1,000 mm <br />1 m <br />) +
5 cm50 mm <br />0.05 m <br /> (90 cm900 mm <br />0.9 m <br />) +