Solidago canadensis L.
golden-rod
Perennial, stoloniferous herb forming dense patches; stems erect, green or tinged reddish, moderately clothed in short hairs, becoming almost glabrous toward base, not branched, up to 2 m tall. Basal lvs withered at flowering; mid cauline lvs narrow-elliptic to elliptic-lanceolate, apetiolate, cuneate, acute to acuminate, usually entire, sometimes serrate, 3-nerved, scaberulous on upper surface and margins, pilose on lower, 8-10-(15) × 1-2-(2.5) cm; uppermost lvs smaller. Infl. a lax, racemose panicle with the individual racemes mostly spreading and secund. Capitula cylindric, (2)-3.5-5 mm diam.; peduncles hairy, 0.5-2 mm long. Inner involucral bracts narrow-oblong, glabrous, (2.5)-3-3.5 mm long; outer bracts narrow-triangular, c. 1.5 mm long. Ray florets c. 8-12; ligules linear-obovate, yellow, 1-3 mm long, recurved. Disc florets 3-5-(6), yellow. Ovary hairy; pappus scabrid; mature achenes not seen.
N.; S.: established locally near settlements throughout.
N. America 1940
Waste places, especially roadsides.
FL Feb-May.
Golden-rod is widely cultivated as an ornamental; it is well established in the wild from cultivation relicts, discarded plants or where it has spread from gardens, although it appears not to produce good seed. There is some variation among wild plants in capitulum size, the extent to which the infl. is secund, and in the degree of serration of the lower lvs. Most wild material has secund infls, entire lvs on most of the stem and relatively large capitula and might be referred to S. canadensis var. scabra Torrey et A. Gray (often treated as a distinct sp. S. altissima L.). Plants with smaller capitula are more typical of S. canadensis. A few collections which match S. canadensis in most characters have less distinctly secund infls and less distinctly 3-nerved lvs. These probably represent cvs of hybrid origin, but with S. canadensis characters predominating; such plants can be distinguished from material closer to S. virgaurea by the fewer disc florets and laxer infl. Variation among wild plants in N.Z. almost certainly results from the establishment of cvs of various origins. Little is likely to be gained by attempting to match these to formal vars of S. canadensis, so most material is best simply included under a broad concept of that sp.
