11. Symphyotrichum novae-angliae (L.) G.L. Nesom (New England aster)

Aster novae-angliae L.

Pl. 245 e, f; Map 1023

Plants perennial herbs, with a compact, woody rootstock, usually with 1 or few short, stout, rhizomatous branches, less commonly the rhizomes slender and longer-creeping. Stems 1 to several, 40–170 cm long, with few to more commonly several ascending to spreading branches above the midpoint, densely and evenly pubescent with more or less spreading hairs (less so toward the base), also with moderate to dense, stalked glands toward the tip. Basal and lower stem leaves absent at flowering, sessile or short-petiolate, the blade 2–6 cm long, 0.5–1.5 cm wide, oblanceolate, tapered at the base, rounded or angled to a usually bluntly pointed tip, the margins entire or sparsely toothed and hairy, the surfaces sparsely pubescent with short, loosely ascending to spreading hairs, appearing more or less 3-veined, the secondary veins on the leaf undersurface relatively easily observed, strongly ascending parallel to the midvein, often fused irregularly toward the tip, the veinlets forming a dense, irregular network of relatively short to somewhat elongate areoles. Median and upper stem leaves often relatively numerous, more or less progressively smaller toward the stem tip, sessile, strongly clasping the stem, the blades 1–12 cm long, narrowly oblanceolate (but often slightly broadened at the base) to narrowly oblong-lanceolate, rarely broader, cordate to nearly truncate at the base, angled or tapered to a sharply pointed tip, the margins entire, hairy, the surfaces moderately to densely hairy, usually with 3 main veins. Inflorescences usually appearing as open panicles, sometimes with solitary heads or small clusters at the tips of short to long branches, the heads appearing mostly long-stalked, the bracts relatively few, 0.5–1.2 cm long, mostly linear. Heads 2.0–4.5 cm (broader in some cultivars) in diameter (including the extended ray corollas) at flowering. Involucre 6–12 mm long, the bracts in 3–6 subequal, overlapping series. Involucral bracts mostly linear, long-tapered to the slender, sharply pointed tip, the tip spreading or reflexed, those of the outer series more or less leaflike, the green portion extending more than 2/3 of the way to the base, those of the median and inner series with a progressively shorter, elliptic, green apical area (this mostly 1/2 the length or more), usually purplish-tinged, the outer surface with relatively dense, stalked glands and often also with sparse, longer, nonglandular hairs (the inner surface sparsely to moderately hairy), the margins with relatively long, spreading hairs. Ray florets 40–100 in usually 2 or 3 series, the corollas well developed, 10–25 mm long, reddish purple to purple (to pink or white elsewhere). Disc florets 50–110, the corollas 4.5–6.5 mm long, the slender portion of the tube shorter than the slightly expanded apical portion, the lobes 0.4–0.7 mm long, 20–25 percent of the total length of the expanded portion. Pappus bristles 4.0–6.5 mm long, mostly pale orangish brown to light tan, occasionally purplish-tinged. Fruits 2–3 mm long, with 7–10 longitudinal ribs, purplish brown to brown, densely hairy and sometimes also sparsely glandular. 2n=10 (rarely 2n=15, 20 in Illinois). July–October.

Scattered nearly throughout the state but apparently absent from the Mississippi Lowlands Division and uncommon in portions of the Glaciated and Unglaciated Plains (eastern U.S. west to Wyoming and New Mexico; Canada; introduced farther west). Bottomland prairies, moist depressions of upland prairies, fens, bases of bluffs, banks of streams and rivers, and margins of ponds and lakes; also pastures, fencerows, banks of ditches, railroads, and roadsides.

Symphyotrichum novae-angliae is perhaps the most popular of our native asters in cultivation. A number of cultivars with different growth forms and various ray corolla colors are available commercially. In the garden, this showy species tends to begin flowering earlier than most of the other asters and to stay in flower a longer time.

An unusual hybrid between this species and S. ericoides has been recorded thus far from Macon, Randolph, and Washington Counties. This hybrid, known as S. Hamethystinum (Nutt.) G.L. Nesom, resembles S. novae-angliae in its relatively large heads with purple ray corollas and relatively broad leaves. However, its involucral bracts lack the strongly reflexed tips and glandular pubescence. Superficially, this hybrid also resembles S. oblongifolium.