Aster Key Online

Online Key to the Asters of New England
(Doellingeria, Eurybia, Ionactis, Oclemena, Sericocarpus, Symphyotrichum)

Stems are densely pubescent, somewhat rough to the touch. The lower-most stem leaves have long, narrowly-winged petioles. Mid-stem leaves have wavy edges (undulate) and shorter, broadly-winged petioles. Rays are blue-violet. Plants of upland woods, clearings & outcrops. Symphyotrichum undulatum

4a.

Mid-stem and some upper stem leaves are heart-shaped with conspicuous notches at the bases of the blades, and are sharply toothed. Phyllaries are ovate (outer) to lanceolate (inner), with short-pointed tips. Green zones are dilated toward the tips of the phyllaries, often tinged with purple.

4b.

Mid- and upper stem leaves are ovate, tapering to broad, winged-petioles, or lacking petioles (upper-most), and do NOT have conspicuous notches at the bases of the blades. Phyllaries are narrowly lanceolate to linear, tapering to long, slender tips. Green zones are long and narrow, mostly confined to the area along the phyllary midveins.

	5a.	Phyllaries bear a short, spine-like (caudate) tip. Branches are sharply ascending. Heads are copious and, congested on branches. Rays are white to pale blue-violet. Plants of various dry to mesic habitats. *Symphyotrichum urophyllum*
	5b.	Phyllaries do NOT bear a short, spine-like (caudate) tip. Branches are spreading to ascending, but not sharply ascending. Heads may be few to many, but are not congested on branches. Rays are blue-violet. Plants of open woods and clearings. Mostly northern New England. Symphyotrichum ciliolatum .

	7a.	Phyllary tips are abruptly recurved. Basal and lower stem leaves are ovate, tapering to abruptly to narrow, winged petioles, with bases that either lack notches or have shallow notches (infrequently). Mid-stem leaves are ovate, borne on shorter winged petioles. Leaves are shallowly or obscurely toothed. (Hybrid of E. macrophylla and E. spectabilis.) Eurybia x herveyi
	7b.	Phyllaries are well appressed (i.e., NOT spreading or recurved). Leaves, especially the basal and lower stem leaves, are very large and sharply toothed, with large notches at the bases of the blades. Plants of rich woods & clearings. Eurybia macrophylla

	8a.	Basal leaves are typically deciduous by flowering. Stems are moderately to strongly bent at the nodes. Plants of woods and clearings. Eurybia divaricata
	8b.	Basal leaves are large and sharply toothed, growing as sterile rosettes, separate from flowering stems. Stems are variously straight or bent at the nodes. Plants of woods and clearings, often on calcareous or sweeter soils. Eurybia schreberi

	13a.	Phyllaries and peduncles are densely glandular. Stems are densely pubescent and rough to the touch. Leaves are lanceolate and toothless, only gradually reduced in size upwards. Rays are purple or magenta, rarely blue-violet or white. Various open habitats, often damp. Symphyotrichum novae-angliae
	13b.	Phyllaries and peduncles are not glandular. Leaves are broadly lanceolate or oblanceolate and toothed. Rays are bright blue-violet, showy. Plants of swamps, wet meadows and ditches.

	14a.	Stems are glabrous below, becoming pubescent in lines above. Leaves are narrowed abruptly to winged, clasping petioles. Stems are often bent at the nodes. Symphyotrichum prenanthoides
	14b.	Stems are stout, densely pubescent and rough to the touch. Leaves are not so narrowed abruptly to winged petioles. Symphyotrichum puniceum

15a.

Heads are numerous, arranged in somewhat congested, one-sided or nearly one-sided arrays on branches. Rays are white. Involucres are vase-shaped, swollen slightly at the base. Phyllary tips are spreading to sometimes recurved. Phyllaries, bracts and leaves have clear, spine-like tips. Leaves are linear to narrowly lanceolate or oblanceolate. Plants of open, disturbed sites.

15b.

Heads are few to many, located mostly at ends of branches, and neither congested nor in one-sided arrays. Stems are glabrous below, pubescent in-lines above. Rays are commonly blue-violet, infrequently nearly white. Plants of salt-marshes, river shores, and other damp habitats. Symphyotrichum novi-belgii

	11b.	Leaves are not clasping.
		Stems are densely short-pubescent. Leaves are narrowly lanceolate to linear, lacking petioles, much reduced on branches and minutely spine tipped. Phyllaries are abruptly recurved and spine-tipped, with conspicuous, dilated green zones. Heads are copious and congested in one-sided arrays on branches. Rays are white. Plants of open, disturbed sites. (Often confused with 15a/15b above.) Symphyotrichum ericoides

	19a.	Rays are white, conspicuous (5 mm or more in length). The capitulescence is lax or open, with few heads, located mostly at the tips of branches. Phyllaries are distinctly triangular in shape, often tinged with purple. Symphyotrichum tenuifolium
	19b.	Rays are inconspicuous (typically much less than 5mm in length). In robust plants, the capitulescence is many branched, with copious heads. Phyllaries are narrowly lanceolate with long, slender tips, often tinged with purple. Rays are pale blue-violet to nearly white. Symphyotrichum subulatum

	20a.	Lobes of the disc corollas are strongly spreading or recurved.
		Disc corollas are pale yellow, cream color or translucent, turning magenta. Rays are white. Heads are small and congested in nearly one-sided arrays on branches. Mostly woods or clearings. Symphyotrichum lateriflorum

22a.

Stems are mostly glabrous and glaucous, though sometimes sparsely hairy in upper leaf axils. Leaves are glabrous, thick and smooth to the touch, lanceolate to oblanceolate or ovate, clasping. Phyllaries are not glandular. Heads are few to many, but not congested on branches. Plants of open woods and other open habitats, usually dry. Symphyotrichum laeve

22b.

Stems are densely pubescent througout, somewhat rough to the touch. Leaves are thick and short pubescent, rough to the touch, ovate to elliptic, very strongly clasping. Phyllaries are densely glandular. Heads are typically few, on widely spreading, straight branches. Plants of various dry, open or open wooded habitats. Symphyotrichum patens

	Stems are variously pubescent, sometimes pubescent in lines. Rays are white or pale blue-violet. Disc florets are yellow. Plants of open, disturbed or sandy sites. Coastal. Symphyotrichum dumosum
23b.	Peduncles are relatively shorter and more nearly uniform in length (typically from 0.2 - 3 cm), with fewer, lanceolate to oblanceolate, bracteal leaflets.
	24a.	In robust plants, branches are ascending to widely spreading, and when longer, often recurved. Heads are often congested in one-sided or nearly one-sided arrays on branches. Stem leaves are narrowly lanceolate or linear, typically bent downwards. Branch leaves are copious, small, oblanceolate, bent backwards on branches. Disc florets are variably pale or dark yellow. Plants of various damp, open habitats. Symphyotrichum racemosum *(View example.)*
	24b.	Branches are mostly ascending but NOT recurved. Heads are neither congested nor in one-sided arrays on branches. Stem leaves are lanceolate or oblanceolate, typically ascending or erect. Rays are white. Disc florets are pale yellow to cream color. Plants of rocky, seasonally-inundated river shores. Symphyotrichum tradescantii *(View example.)*

17b.

Phyllaries are appressed, though not tightly. The tips of the outer series of phyllaries are often spreading. Occasionally some of the inner phyllaries are also spreading. Green zones are often dilated toward the tips of the phyllaries, but are usually basally elongated. (i.e., not diamond-shaped) Some phyllaries, especially the outer-most, may be almost green throughout. Stems are glabrous below, becoming pubescent in lines upwards. Rays are commonly white or pale blue-violet. Plants of disturbed sites, roadsides, old meadows and thickets, often damp. Colonial from rhizomes.

	25a.	Stems are glabrous and glaucous, often reddish. Leaves are narrowly lanceolate, somewhat thick, with a conspicuous network of raised veins (rugose), and with edges that are slightly curled under (revolute). Rare. Symphyotrichum praealtum
	25b.	Stems are glabrous but not glaucous, typically green. Leaves are broadly to narrowly lanceolate, but thin and flat, with edges that are not curled under.

	26a.	Leaves are broadly lanceolate or oblanceolate, not greatly reduced upwards or on flowering branches. Symphyotrichum lanceolatum var latifolium
	26b.	Leaves are lanceolate or oblanceolate, slightly reduced in size upwards, and particularly on flowering branches . Symphyotrichum lanceolatum var lanceolatum .

	29a.	*The phyllaries are densely glandular.* Stems are densely short-pubescent. The basal and lower stem leaves are ovate to spatulate, on long petioles. Stem leaves are oblanceolate or elliptic. Phyllaries are densely stipitate-glandular. Rays are bright blue-violet or magenta, showy. Plants of sandy places; coastal plain. Eurybia spectabilis
	29b.	The phyllaries are NOT glandular. Mid- and upper stem leaves are lanceolate or oblanceolate, obscurely toothed or lacking teeth, with short-pointed tips. Both rays and disc florets are white. Heads are often lacking petioles and are grouped closely into tight clusters (glomerules). Plants of open disturbed sites or open woods. Sericocarpus asteroides

	31a.	The phyllaries are densely glandular. Stems are stout, densely pubescent and rough to the touch. Rays are commonly purple or magenta, rarely pale violet or white. Plants of various open sites, often damp. Symphyotrichum novae-angliae
	31b.	The phyllaries are not glandular. Leaves are oblanceolate, narrowed somewhat abruptly to broad, winged, flaring petioles. Stems are glabrous below, becoming pubescent in-lines above. Rays are blue-violet, showy. Plants of swamps, roadside ditches or wet meadows. Rare. Symphyotrichum prenanthoides

	32a.	Stem leaves are linear to narrowly elliptic, untoothed, and mostly blunt or short tipped. Stems are glabrous to sparsely pubescent. Stem leaves are copious and slightly congested. Rays and disc florets are white. Plants of rocky or sandy `habitats, open woods to full sun. Sericocarpus linifolius
	32b.	Stem leaves are ovate to lanceolate/oblanceolate, toothed, and with sharp-pointed tips. Disc florets are yellow, rays pale blue-violet. Heads are few, not one-sided on branches. Green zones are dilated at tips of phyllaries, not basally elongated. Plants mostly of damp wooded habitats. Eurybia radula

34a.	Stems are pubescent throughout. Heads are nodding in bud. Seeds are covered with minute stalked glands.
	35a.	Stem leaves are broadly ovate to obovate, sharp toothed and taper to long slender tips. Leaves appear whorled in immature plants. The largest leaves are at mid-stem, and are reduced in size upwards and downwards. Phyllaries are narrow, tapering to slender tips, appressed, not glandular or sparsely glandular. Rays are white, long. Plants of low, damp woods or cool, wooded mountain slopes. Oclemena acuminata
	35b.	Stem leaves are lanceolate to elliptic, obscurely toothed or nearly untoothed, and have short-pointed tips. Leaves are oblanceolate, shallowly toothed or untoothed, not appearing whorled in immature plants. Phyllaries are linear-lanceolate, appressed to slightly spreading-recurved (outer series). Rays are pale blue-violet to white. Plants of low, damp woods. (Hybrid of O. acuminata and O. nemoralis.) Oclemena x blakei
34b.	Stems are glabrous below the capitulescence. Heads are not nodding in bud. Seeds are not glandular.
	Leaves are ovate or obovate, tapering to broad, short (cuneate) petioles. Stems are thin, glabrous below, becoming short-pubescent above. Rays are white. Pappus bristles in 2+ series: a very short outer series, and at least one inner series of much longer bristles. Plants of rich upland woods. Doellingeria infirma

	36a.	Stems are glabrous below the capitulescence. Stem leaves are ovate, elliptic or broadly lanceolate. Heads are not nodding in bud.
		Leaves are lanceolate, becoming elliptic and gradually reduced in size upwards, with long-pointed tips. Rays are white. Pappus bristles are in 2+ series: a very short outer series and at least one inner series of much longer bristles. Colonial from rhizomes. Stout plants of thickets, damp, open woods and other damp places. Doellingeria umbellata

		37a.	Leaf edges are curled under (revolute). Leaves are pubescent, rough to the touch, and glandular on the undersides. Heads are borne on long, leafy peduncles. Seeds are covered with minute stalked glands. Plants of bogs and pond margins on floating sphagnum mats. Oclemena nemoralis
		37b.	Leaf edges are flat (NOT curled under). Leaves are glabrous and not glandular on the undersides. Stems are densely short-pubescent. Stem leaves are copious and congested. Rays are pale blue-violet to nearly white. Short plants of dry rocky or sandy habitats, open woods to full sun. Ionactis linariifolia

	16a.	Stems are sparsely to densely pubescent. Leaves have long, +/- straight hairs. *Symphyotrichum pilosum var pilosum*
	16b.	Stems and leaves are mostly glabrous. *Symphyotrichum pilosum var pringlei*

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1b.	The basal and lower-most stem leaves are NOT heart-shaped and borne on long petioles.