Taxonomy

Solidago canadensis L., Sp. Pl. 2: 878. 1753.

Common synonyms

Aster canadensis (L.) Kuntze Revis. Gen. Pl. 1: 317. 1891; Doria canadensis (L.) Lunell Amer. Midl. Naturalist 5: 43. 1917.

Common name

Canadian goldenrod

Description

Propagule or dispersal unit is the fruit with pappus. Fertile part 0.75-1 mm long, 0.2-0.4 mm wide, in side view widest in upper part (obovoid) or widest in the middle, +/- straight, the upper (apical) end narrowing, rarely suddenly cut off (truncate) (by misinterpretation), in cross-section round (terete) (?) or 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, thickened margin absent, longitudinal ribs present, 3-5, their surfaces smooth, with simple straight hairs.

Pappus type bristles / hairs, pappus elements all +/- similar, rarely clearly differentiated (by misinterpretation), up to 1.25-2.5 mm long, in one row, pappus elements numerous, persistent, the individual bristles rough / serrated (barbellate), +/- equal width along length, white / translucent.

Notes: The three Solidago species included in this key can be differentiated by the size of their fruits. Solidago canadensis has a fertile part of less than 1 mm in length, Solidago gigantea 1-2 mm, and Solidago virgaurea 2-4 mm.

Ecology

Perennial herb, fruits wind-dispersed. Temperate areas, from dry grassland to edges of wetlands. Particularly common on rail- and roadsides, wastelands, and urban areas, less frequently on agricultural land, natural grasslands, river margins and wetlands.

Native range

Canada, United States, Mexico.

Introduced range

Nicaragua, widespread through most of Europe, Turkey, Georgia, India, China, Japan, Australia, New Caledonia, New Zealand, Cook Islands.

Past interceptions (Australia): origins

Other or unidentified species of the genus from Canada, United States, Spain, France, Slovakia, Hungary, UAE, Sri Lanka, Japan, Korea, Thailand.

Past interceptions (Australia): commodities

Other or unidentified species of the genus in/on nursery stock, machinery and parts, new vehicles, curry leaves, new tyres.