Flora of New Zealand Series

fireweed

Erect annual to short-lived perennial herb. Mid cauline lvs hispid with short hairs on upper surface and longer, denser, jointed hairs on lower, rarely only sparsely hispid, apetiolate, narrow, ovate, lanceolate, oblong or elliptic, pinnately lobed to 1-pinnatifid with lanceolate to oblong, entire to few-toothed segments, usually amplexicaul and deeply 2-3-fid at base, 5-10-(14) × 1-3-(4) cm. Uppermost lvs smaller, usually lanceolate, and often dentate and not lobed. Supplementary bracts 4-7, 1-2 mm long. Involucral bracts (8)-10-13-(14), glabrous, 5-6 mm long. Ray florets 0. Disc yellow, 1-2 mm diam. Achenes ellipsoid-subcylindric, slightly constricted below apex, with (1)-2-3-(4) rows of hairs in grooves between broad ribs, 1.5-1.8 mm long.

N.: Northland, vicinity of Auckland City, Coromandel, Opotiki District, Wellington Province; S.: Nelson, Marlborough, N. Canterbury.

Also indigenous to Australia.

Waste places, forest margins and clearings, coastal sites, riverbeds and damp areas.

FL Oct-Apr-(Aug).

Drury (op. cit.) recognised 2 components among N.Z. material of S. hispidulus; he suggested that plants in the northern North Id may be naturalised in N.Z., whereas he noted that there is little evidence on which to decide whether the plants in the Wellington area and northern South Id are indigenous or naturalised. None of the characters Drury listed can be reliably used to separate individual plants of the 2 components because there is considerable variation in both groups; he wisely noted that there would be little value in giving names to the 2 sorts. S. hispidulus is very similar in vegetative characters to S. scaberulus (Fig. 30), but can be easily distinguished from that sp. by the short, cigar-shaped achenes with few hairs.

S. hispidulus is now much more common and widespread than S. scaberulus.

Belcher (op. cit.) treated S. scaberulus and S. hispidulus as var. scaberulus and var. hispidulus respectively of S. hispidulus. Allan (1961) did not accept these 2 vars and treated all mainland N.Z. material as Erechtites scaberula, but described Chatham Is material as E. scaberula var. chathamica. Drury (1974, op. cit.) raised var. scaberula to specific rank as S. scaberulus and placed Allan's var. chathamica in synonomy under it. Drury's treatment is followed here.