1. Aster tataricus L.f. (Tatarian aster)
Map 961
Plants perennial
herbs, with stout rootstocks, often densely colonial from relatively thick,
somewhat fleshy rhizomes. Stems 1 to several, 50–200 cm long, erect or
ascending, often with several to numerous ascending branches above the
midpoint, moderately to densely roughened, with short, broad-based hairs toward
the tip, glabrous to sparsely hairy toward the base. Basal leaves persistent at
flowering, robust, mostly 30–50 cm long, 3–10 cm wide, the
blade oblanceolate to narrowly elliptic, narrowed or short-tapered to a sharply
pointed tip, long-tapered to the base, the margins shallowly toothed, the
surfaces and margins roughened with sparse to moderate, short, broad-based
hairs. Stem leaves gradually reduced toward the tip, 3–30 cm long,
narrowed or short-tapered to a sharply pointed tip, tapered to a sessile,
somewhat sheathing but not strongly clasping base, the margins entire to
shallowly toothed, the surfaces and margins roughened with sparse to moderate,
short, broad-based hairs. Inflorescences often elongate panicles (rarely
reduced to a solitary terminal cluster), the heads in flat-topped to somewhat
rounded clusters at the ascending branch tips, the bracts relatively numerous,
leaflike, linear to narrowly oblong-elliptic or narrowly oblanceolate. Heads
radiate, not sticky or resinous. Involucre 7–12 mm long, cup-shaped to
slightly bell-shaped. Involucral bracts in 3 or 4 unequal, overlapping series,
linear to narrowly lanceolate, the tip ascending and often somewhat
purplish-tinged, poorly differentiated into a green central band and lighter
margins, the margins sometimes somewhat irregular, occasionally sparsely hairy
toward the tip, the outer surface glabrous or sparsely hairy. Receptacle flat
or slightly convex, with minute, irregular ridges around the concave attachment
points of the florets. Ray florets 15–30, pistillate, the corolla
10–15 mm long, pale lavender to purple or purplish blue. Disc florets
25–50, perfect, the corolla 4–6 mm long, yellow, often turning
purplish after the pollen has been shed, not persistent at fruiting. Pappus of
the ray and disc florets similar, of numerous capillary, finely barbed bristles
in 2 similar series, 6–8 mm long, white or cream-colored. Fruits
1.5–2.0 mm long, narrowly obconical, not or only slightly flattened,
4–6-ribbed, glabrous to finely hairy, light brown to tan. 2n=54.
September–November.
Introduced,
uncommon and sporadic, mostly near urban areas (native of Europe, Asia,
introduced sporadically in the eastern U.S. west to Iowa and Missouri). Banks
of streams; also gardens and moist, disturbed areas.
Tatarian aster
is a striking and robust plant that is grown as an ornamental in gardens. Under
some conditions, it can be relatively aggressive, forming dense colonies from
the rhizomes. This species was first reported from Missouri by Yatskievych and
Summers (1993) based on collections made in the 1970s in Jefferson County by James Solomon of the Missouri Botanical Garden.