1. Boltonia asteroides (L.) L’Hér. (false aster, false starwort)
Pl. 231
f–i; Map 963
Plants producing
basal offshoots and often also elongate rhizomes. Stems 40–150 cm long
(taller in some cultivated forms). Leaf blades 2–15 cm long,
4–25 mm wide, those of the lower and median leaves oblanceolate to
narrowly elliptic, those of the upper leaves narrowly oblanceolate to linear,
the base not decurrent below the attachment point (the stems thus unwinged).
Inflorescences appearing leafy, the bracts 1.5–5.0 cm long, 2–6
mm wide. Heads relatively large, the receptacle usually 6–14 mm in
diameter at flowering. Involucre 3–5 mm long, the bracts in mostly 3
subequal series. Ray florets 25–60, the corolla 7–15 mm long.
Disc florets 60–180. Pappus of disc florets a short, irregular crown of
awns or narrow scales 0.1–0.4 mm long and 2(–4) awns
0.5–2.0 mm long, the longer awns mostly well developed in the disc
florets, often absent in the ray florets. Fruits 1.5–3.0 mm long, the
wings 0.1–0.5 mm wide. 2n=18, 36. July–October.
Scattered nearly
throughout the state (eastern U.S. west to North Dakota and Texas; Canada; introduced in Idaho, Oregon). Banks of streams and rivers, margins of ponds and lakes,
bottomland prairies, bottomland forests, sloughs, fens, and marshes, also
margins of crop fields, fallow fields, levees, banks of ditches, railroads,
roadsides, and moist, sandy, disturbed areas.
Boltonia
asteroides is the most
common species of Boltonia in the state. In recent years, it has become
popular as an ornamental in native plant gardens throughout the eastern and
central United States because of its tolerance to deer browsing and the
beautiful white blooms it produces in the autumn. Fruits of this species are
commonly eaten by waterfowl.
Currently there
are three varieties of this species accepted by most authors, only two of which
are found in Missouri. The var. asteroides differs in its subequal,
relatively narrow involucral bracts and slightly shorter pappus awns. It occurs
mainly along the Atlantic and Gulf Coastal Plains.