Flora of New Zealand Series

fireweed

Erect annual to short-lived perennial herb. Mid cauline lvs hispid with short to long jointed hairs on upper surface and long jointed hairs on lower, apetiolate, narrow- to ovate-elliptic, dentate to pinnately lobed or 1-pinnatifid with triangular to narrow-oblong, few-toothed segments, not amplexicaul to amplexicaul and dentate or 1-3-fid at base, (3)-7-12-(18) × (0.5)-2-5 cm. Uppermost lvs smaller, usually lanceolate and more often dentate or only shallowly lobed. Supplementary bracts 4-6, 1-2 mm long. Involucral bracts 10-13, glabrous, (5)-6-7 mm long. Ray florets 0. Disc yellow, c. 2 mm diam. Achenes subcylindric, slightly constricted below apex, usually ± evenly hairy, (2)-2.2-2.6-(3), mm long.

N.: Northland S. to Hauraki Gulf including offshore islands, Puru R. and Raglan (S. Auckland); S.: collected from Picton, Akaroa, and Dunedin, but not seen recently; Ch.

Endemic.

Coastal habitats, scrubland, forest margins and clearings.

FL Oct-Feb.

Most recent collections of this sp. are from N. offshore islands; it was formerly much more widely distributed. S. scaberulus is similar to the much more common S. hispidulus (Fig. 30), and is most reliably distinguished from that sp. by its long, narrow, usually evenly hairy achenes which are narrowed below the apex. These 2 spp. were treated as vars of S. hipidulus by Belcher (op. cit.) but were not distinguished by Allan (1961) who treated N.Z. material of both taxa as Erechtites scaberula. Drury (op. cit.) placed Allan's var. chathamica in synonomy under S. scaberulus. The achenes of S. scaberulus are similar to those of S. sylvaticus, which is distinguished by the non-hispid lf hairs and usually by small-rayed outer florets.

Drury (op. cit.) recorded S. apargiaefolius Walp. for N.Z. based on a single gathering (CHR 333911, near Flax Bridge, Kaiaka-Kaitaia Road, Mongonui, Carse, 2.11.1915). Belcher has suggested that this material is closer to S. gunnii (Hook. f.) Belcher although the lvs lack white-lanate hairs on the lower surface. As this plant has not been collected again, it seems more likely that the material is of hybrid origin with the lf hairs indicating S. scaberulus or S. hispidulus as one of the parents.