Flora of New Zealand Series

Umbels simple, terminal on peduncle; involucral bracts several, ± ovate to lanceolate; calyx-teeth obsolete; petals us. white, acute, inflexed, imbricate. Fr. of oblong-ovoid order, slightly laterally compressed. Mericarps subterete, with 5 equal, blunt, us. conspicuous ribs, 2 close to commissure. Vittae 1 per furrow and 2 on commissural face. Seed nearly terete, grooved on commissural face. Tufted perennial herbs with pinnately divided to compound lvs. A genus of some 20 spp. of Central and S. America, Australia, N.Z., New Guinea.

Hooker (Handbk N.Z. Fl. 1864, 91) recognized 3 spp. for N.Z. and (loc. cit. 1867, 729) said of O. andicola Endl., "A native of Australia and Chili; is erroneously stated in Benth. Fl. Austral. iii. 337, to be a native of N. Zealand." Kirk (Stud. Fl. 1899, 197) and Cheeseman (Man. N.Z. Fl.1925, 655) place all our forms under O. andicola Endl.  Gen. Pl. 1839, 787. They admit Hooker's spp. as vars, but do not state what forms, if any, they place under O. andicola sens. strict . Certain forms of O. colensoi approach O. andicola, as represented in K, very closely. The N.Z. group is very difficult to analyse from herbarium specimens, although these are plentiful, but not well annotated. There are linking forms between all the described forms. Kirk (Stud. Fl. 1899, 198) remarks: "They pass into each other so insensibly that it is impossible to draw permanent lines of separation." Cheeseman (Man. N.Z. Fl. 1925, 656) considers: "Any large series of specimens will show that the development or non-development of a branched stem, and the amount of pubescence . . . are in Oreomyrrhis far too variable and inconstant to be employed" for the separation of the spp. Nothing short of "mass" collections and genetic studies will resolve the complex. The plants are easy to grow. A. P. Druce has made extensive studies of North Id forms both in the field and garden. He has kindly forwarded 15 specimens and a map showing their location.

Mathias and Constance (Univ. Calif. Publ. Bot. 27, 1955, 347-416) have monographed the genus. For N.Z. (pp. 371-381) they accept the three spp. recognized in this account. They remark: "it may be emphasized that none of the New Zealand plants appears to be conspecific with any of the Australian or Tasmanian or, least of all, with any of the American species."

The 3 spp. here recognized are linked by intergrading forms partly due to response to habitat, but mainly probably to hybridism. FL. 9-2. FT. (9)-10-3-(5).