Flora of New Zealand Series

Scrambling shrub; primocanes low-arching and interlacing, distinctly whitish pruinose, becoming reddish, ± sharply angled and ± flat between, with few subsessile glands, and usually sparsely to moderately clothed in mostly stellate hairs, rarely finally glabrous; armature of few to many stout, erect to slightly falcate prickles on angles. Young stems with stellate tomentum, and scattered simple hairs and subsessile glands. Leaflets 5, glabrous or almost glabrous on upper surface, pilose on veins and with dense whitish tomentum between on lower surface, 1-2-serrate; terminal leaflet lamina oblong to narrow-obovate, acuminate, 30-80 × 20-50-(60) mm, with petiolule ⅓-⅖ length of lamina. Stipules linear. Infl. densely hairy, with subsessile glands. Sepals acuminate, tomentose and with very few, longer, simple hairs, usually without but sometimes with pricklets. Petals rounded, strongly crinkled, bright pink. Anthers glabrous.

N.: N. Auckland to Wellington, especially Hawke's Bay and N. Wellington Province; S.: Nelson, vicinity of Christchurch, Otago (Lawrence); St.: Halfmoon Bay area.

Europe, N.W. Africa, Macaronesia 1899

Roadsides, streamsides, waste places, neglected pasture, hillsides, margins of forest and scrub.

FL Nov-Mar FT Feb-Apr.

R. ulmifolius is probably the only diploid (2 n = 14), sexually reproducing member of the R. fruticosus agg. occurring in N.Z. It is somewhat variable but is usually easily distinguished by the pruinose stems, small leaflets and bright pink petals. In addition, it is distinguished from R. procerus by the very fine tomentum with few simple

hairs on the sepals (Fig. 103). Clapham, A. R., Tutin, T. G. and Warburg, E. F., Excur. Fl. Brit. Is ed. 3 (1981), accepted the earlier name R. inermis Pourret for this sp. As this change is not accepted by some other authorities, the more familiar R. ulmifolius is used here. R. ulmifolius was first recorded in N.Z. as R. rusticanus and some early records of R. discolor may also apply to this sp.

R. ulmifolius readily forms fertile hybrids with other members of the R. fruticosus agg. The following have been collected in N.Z.: R. cissburiensis × R. ulmifolius which is given a full treatment, and R. erythrops × R. ulmifolius which is treated under R. erythrops. R. ulmifolius × R. vestitus has been collected near Tauranga, and Pauatahanui Inlet (Wellington) (e.g., CHR 415411, Given 13433 and Hall, 5.12.1983); it is similar to R. vestitus, but is lower growing with reddish, glabrate stems and pale undersides to the leaflets.