Flora of New Zealand Series

fireweed

Erect annual or short-lived perennial herb. Mid cauline lvs sparsely white- lanate on upper surface, usually densely white-lanate on lower, very rarely becoming only sparsely hairy, apetiolate, elliptic to narrow-oblong, pinnately lobed with oblong to obovate, entire or few-toothed segments, amplexicaul and dentate at base, 5-17 × 1.5-4 cm. Uppermost lvs smaller, often lanceolate, usually dentate and not lobed, rarely entire. Supplementary bracts 8-14, 1-2.5 mm long. Involucral bracts 13-(14), usually lanate toward base, (4)-4.5-6 mm long. Ray florets 0. Disc yellow, 2-3 mm diam. Achenes ellipsoid-subcylindric, slightly constricted below apex, usually with 1-3 rows of hairs between ribs, sometimes evenly hairy, 1.2-1.6 mm long.

N.; S.: throughout; St.; Ch.

Also indigenous to Australia and W. U.S.A..

Common in waste places, especially roadsides and stony sites, forest margins and clearings, coastal sands and cliffs, also in shrubland, grassland, and swamps from sea level to 1000 m.

FL Nov-Mar-(Oct).

S. glomeratus is a very common sp., distinguished by the lanate, lobed and toothed lvs (Fig. 30), and short bracts and achenes. It was treated in Erechtites by Allan (1961) as E. arguta. Drury (op. cit.) also included within his circumscription of S. glomeratus, Chatham Is plants described by Allan (1961) as var. traversii of E. quadridentata. Some material from Ch. differs from that of mainland N.Z. in being generally more hairy, having less divided lvs (Fig. 30), and in the achenes which are evenly hairy rather than having the hairs confined to stripes; the short cigar-shaped achenes clearly place this form with S. glomeratus rather than S. quadridentatus. Some material from S. South Id differs in having almost glabrous, less divided lvs, but is referable to S. glomeratus on other characters; such plants can be distinguished from related spp. by the woolly hairs at base of the involucre.