Taxonomy

 Symphyotrichum subulatum (Michx.) G.L.Nesom, Phytologia 77(3): 293. 1995.

Common synonyms

Aster subulatus Michx., Fl. Bor.-Amer. (Michaux) 2: 111. 1803.

Common name

Annual saltmarsh aster

Description

Propagule or dispersal unit is the fruit with pappus. Fertile part 2-2.6 mm long, 0.2-0.5 mm wide, in side view widest in upper part (obovoid) or widest in the middle, +/- straight, the upper (apical) end narrowing, in cross-section flattened, basal scar (carpopodium) pronounced and well-differentiated, central, beak (=thinner sterile stalk between seed and pappus) absent, wings absent, fruit surface light brown or straw, smooth (except at cellular level), with simple straight hairs, glands or glandular hairs (?) or papillae (small protuberances) (?), thickened margin absent, longitudinal ribs present, 4-7, their surfaces smooth, with simple straight hairs.

Pappus type bristles / hairs, pappus elements all +/- similar, rarely clearly differentiated (by misinterpretation), up to 4-6 mm long, in one row, pappus elements numerous, persistent, the individual bristles rough / serrated (barbellate), +/- equal width along length, white / translucent.

Notes: Unfortunately, the Symphyotrichum species cannot be differentiated in this fruit key.

Ecology

Annual herb, fruits wind-dispersed. Temperate to subtropical climates, some varities saline tolerant. Found in marshes including coastal salt marshes, roadsides, lawns, wastelands, and urban areas.

Native range

Canada, United States, Mexico, Central America, Caribbean, Venezuela, Brazil, Bolivia, Argentina, Chile, Paraguay, Uruguay.

Introduced range

Korea, Japan, Taiwan, Australia, New Zealand.

Past interceptions (Australia): origins

China.

Other or unidentified species of the genus from Colombia, Ecuador, Spain, Italy, China, Korea, Japan, Thailand.

Past interceptions (Australia): commodities

Containers.

Other or unidentified species of the genus in/on containers, cut flowers, new vehicles, steel, and soil.