Flora of New Zealand Series

Type locality: Mount Hikurangi. Type: W, DM. 165, N. Potts.

Low-growing summer-green subshrub with slender, quadrangular, branching stems up to ± 4 dm. long, arising from slender, branched rhizomes. Branches and branchlets very slender. Lvs opp. distant, subsessile or on slender petioles hardly 0·5 mm. long. Lamina oblong to broad-ovate, ± apiculate, rounded at apex, truncate at base, submembr., us. purplish, (5)-6-8-(9) × (4)-5-6-(9) mm., margins sinuate-undulate. Racemes terminal on stems and sts on main branches, 4-14 cm. long. Fls distant, on slender pedicels up to 7 mm. long; sepals broad-ovate, ± toothed, c. 1·5 mm. long; petals similar; carpels 5, ribbed.

DIST.: N. Mount Hikurangi, Mount Parikanapa.

POLYMORPHY AND HYBRIDISM

Kirk (Stud. Fl. 1899, 97) remarked, "All the New Zealand forms are perennial; they vary to a remarkable extent, and should probably be referred to a single species." This is an echo of the view of Lindsay (loc. cit. 83). In K he found "such a continuity of variation-such a connection of so-called species by intermediate or passage-forms-that it appeared impossible to define or limit them by any permanent characters of sufficient value." The part played by hybridism in producing the multiplicity of forms seen in the field has been much discussed, but no experimental work appears to have been done. For accounts and illustrations see: Cockayne and Allan in T.N.Z.I. 57, 1927, 51; Allan in Genetica 9, 1927, 151; Allan in Rep. Aust. Ass. Adv. Sci. 20, 1931, 446; Oliver in Rec. Dom. Mus. Wellington 1, 1942, 36. Oliver recognizes the following groups: arborea × pteridoides, × kingiana, × plumosa; sarmentosa × angustissima, × plumosa, × kingiana; kingiana × pottsiana. Most probably there is crossing between arborea and sarmentosa.