Flora of New Zealand Series

; Holotype: CHR 218503! P. Wardle Landsborough up valley from Spencer Glacier, Sth Westland, 4100 ft. on sunny moraine terrace, with Chion[ochloa] oreophila, 14.3.1971.

Slender tussock with stramineous, hairy sheaths. Leaf-sheath to 10 cm, hairy, entire, margins often undulating, apical tuft of hairs to 3.5 mm. Ligule to 0.5 mm. Leaf-blade to 30 cm × 2.5 mm, flat or ± U-V-shaped, keeled, twisting above, disarticulating at ligule, abaxially prickle-toothed above, adaxially with prickle-teeth; margin with long hairs below, becoming prickle-toothed or rarely becoming smooth. Culm to 60 cm, slender, internodes glabrous. Inflorescence to 13 cm, glabrous except for long hairs at branch axils. Spikelets golden and purple, of up to 8 florets. Glumes usually > nearest lemma lobes; lower to 10 mm, 1-3-5-nerved, upper to 11 mm, 3-5-7-nerved. Lemma to 5.5 mm; hairs dense on margin and aside central nerve, sparse or absent elsewhere; lateral lobes to 4 mm, shortly awned or triangular-acute; central awn to 7 mm from a flat, rarely twisting, column to 2 mm. Palea to 7 mm. Callus to 1 mm, hairs to 2.5 mm. Rachilla to 1 mm. Lodicules to 1 mm. Anthers to 3.5 mm. Gynoecium: ovary to 1 mm; stigma-styles to 2 mm. Caryopsis to 2 mm.

S.: Close to Main Divide from south Canterbury to Fiordland. Grasslands; 1200-1600 m.

Endemic.

HYBRIDS

Chionochloa ×elata (Petrie) Connor, N.Z. J. Bot. 29: 272 (1991) ≡Danthonia oreophila var. elata Petrie, T.N.Z.I. 45: 274 (1913) ≡Chionochloa oreophila var. elata (Petrie) Zotov, N.Z. J. Bot. 1: 104 (1963) ≡Chionochloa elata (Petrie) Connor, N.Z. J. Bot. 19: 166 (1981); Lectotype: WELT 36436! D. P[etrie] Sealy Range, Mt Cook, 5000 ft, Feb. 1911 (designated by Zotov 1963 op. cit. p. 104).

Because this hybrid has a formal name it is described in full:

Slender yellow tussock of modest stature with shining leaves disarticulating at ligule. Leaf-sheath to 15 cm, entire, apical tuft to 3.5 mm. Ligule to 0.5 mm. Leaf-blade to 30 cm × 3 mm, ± flat or U-shaped, keeled, drawn out to long thin spiralling point, abaxially smooth and glabrous except for prickle-teeth above and sometimes long internerve hairs, adaxially with abundant prickle-teeth; margin with long hairs below, prickle-teeth above. Culm to 60 cm, internodes glabrous. Inflorescence to 15 cm. Spikelets of up to 7 golden and lightly purpled florets. Glumes > nearest lemma lobes; lower to 9 mm, 3-nerved, upper to 11 mm, 1-3-5-nerved, glabrous. Lemma to 5.5 mm; hairs dense at margin and aside main nerve, and in most internerves; lateral lobes to 4.5 mm including awn to 1 mm or long triangular-acute; central awn to 10 mm reflexed from flat column up to 2 mm. Palea to 7 mm. Rachilla to 1.5 mm. Anthers to 3.75 mm. Gynoecium: ovary to 0.75 mm; stigma-styles to 2.75 mm. Caryopsis to 2.5 mm.

S.: Sealy Range, Mt Cook. Alpine and subalpine grasslands; 1200-1700 m.

Connor (1991 op. cit.) restricted the name solely to plants from the Sealy Range, Mt Cook National Park; they are local C. oreophila × C. pallens subsp. cadens.

To thirty five interspecific hybrid combinations described in detail by Connor (1991 op. cit.), C. beddiei × C. flavescens and C. conspicua × C. flavescens are now added. Localised distribution of some species limits the extent of interspecific hybridisation: C. acicularis × C. oreophila (Fiordland), C. acicularis × C. rubra (Fiordland), C. australis × C. conspicua (Nelson), C. australis × C. crassiuscula (Canterbury), C. australis × C. macra (Marlborough), C. australis × C. oreophila (Nelson and Canterbury), C. australis × C. pallens (Nelson and Marlborough), C. australis × C. rubra (Nelson), C. beddiei × C. cheesemanii (Wellington), C. beddiei × C. flavescens (Marlborough Sounds), C. cheesemanii × C. conspicua (Urewera N.P., Manawatu, Nelson), C. cheesemanii × C. rubra (north-west Nelson), C. conspicua × C. flavescens (Tararua Range), C. conspicua × C. rubra (Egmont, central North Id, Nelson, Canterbury, Mt Cook, Stewart Id), C. conspicua × C. pallens (Gisborne), C. crassiuscula × C. lanea (Stewart Id), C. crassiuscula × C. oreophila (Canterbury), C. crassiuscula × C. pallens (Canterbury), C. crassiuscula × C. rigida (south Westland, Stewart Id), C. crassiuscula × C. rubra (Stewart Id), C. crassiuscula × C. teretifolia (Southland), C. flavescens × C. macra (Canterbury), C. flavescens × C. oreophila (Mt Cook), C. flavescens × C. pallens (Tararua Range, Marlborough, Westland), C. flavescens × C. rubra (Tararua Range, Nelson, Buller, Canterbury), C. macra × C. oreophila (Southern Alps), C. macra × C. pallens (Southland), C. macra × C. rigida (Canterbury), C. macra × C. teretifolia (Southland), C. oreophila × C. pallens (Nelson, Westland), C. oreophila × C. teretifolia (Fiordland), C. pallens × C. rigida (Fiordland), C. pallens × C. rubra (central North Island, Nelson, Marlborough), C. rigida × C. rubra (Canterbury, Otago), C. rigida × C. teretifolia (Fiordland, Southland), C. rubra × C. spiralis (Fiordland), C. spiralis × C. teretifolia (Fiordland).

Experimental interspecific hybrids were fertile, as were those which occurred spontaneously in the experimental garden [Connor, H. E. N.Z. J. Bot. 5: 3-16 (1967)]. Seeds, often present in natural interspecific hybrids, are consistent with experimental results.

REPRODUCTIVE BIOLOGY

Reproduction is by seeds. All species are chasmo-gamous and anthers and stigmas are simultaneously exserted at anthesis. Most of the pollen produced by C. pallens subsp. pilosa comes from the largest plants [McKone, M. J. New Phytol. 116: 555-562 (1990)]. All species tested are self-compatible [Connor, H. E. N.Z. J. Agric. Res. 3: 728-733 (1960); Connor, H. E. N.Z. J. Bot. 5: 3-16 (1967)]; McKone, M. J., Thom, A. L. and Kelly, D. N.Z. J. Bot. 35: 259-262 (1997) experimentally demonstrated self-compatibility in C. macra and C. pallens. Self-pollination is not exclusive as the widespread occurrence of natural hybrids indicates (vide supra). Connor, H. E. N.Z. J. Bot. 5: 3-16 (1967) suggested that C. flavicans might be apomictic but there is no confirming evidence. Gynodioecism occurs in C. bromoides; female frequency is very variable - 58.2 % on Poor Knights Islands and zero in several populations on the mainland [Connor, H. E. N.Z. J. Bot. 28: 59-65 (1990)].

CHEMOTAXONOMY

(1) Epicuticular leaf wax composition: (a) lipids [Cowlishaw, M. G., Bickerstaffe, R. and Young, H. Phytochem. 22: 119-124 (1983); Cowlishaw, M. G., Bickerstaffe, R. and Connor, H. E. Biochem. Syst. Evol. 11: 247-259 (1983); Savill, M. G., Bickerstaffe, R. and Connor, H. E. Phytochem. 27: 3499-3507 (1988)]; 20 spp.; (b) triterpene methyl ethers: [Russell, G. B., Connor, H. E. and Purdie, A. W. Phytochem. 15: 1933-1935 (1976); Connor, H. E. and Purdie, A. W. N.Z. J. Bot. 14: 315-326 (1976), N.Z. J. Bot. 19: 161-170 (1981); Pauptit, R. A. et al. Aust. J. Chem. 37: 1341-1347 (1984); Rowan, D. D. and Russell, G. B. Phytochem. 31: 702-703 (1992)]; data are summarised in Connor (1991 op. cit.); triterpene methyl ethers are not universally found in the 22 spp. analysed. (2) Structural polysaccharide composition [Connor, H. E. et al. N.Z. J. Agric. Res. 13: 534-554 (1970); Bailey, R. W. and Connor, H. E. N.Z. J. Bot. 10: 533-544 (1972); Connor, H. E. and Bailey, R. W. N.Z. J. Bot. 10: 515-532 (1972)]; carbohydrates [Payton, I. J. and Brasch, D. J. N.Z. J. Bot. 16: 435-460 (1978)]. (3) Concentration of inorganic elements [Connor, H. E., Bailey, R. W. and O'Connor, K. F. N.Z. J. Agric. Res. 13: 534-554 (1970); Molloy, B. P. J. and Connor, H. E. N.Z. J. Bot. 8: 132-152 (1970); O'Connor, K. F., Connor, H. E. and Molloy, B. P. J. N.Z. J. Bot. 10: 205-224 (1972); Williams, P. A. N.Z. J. Bot. 15: 399-442 (1977); Williams, P. A., Mugambi, S. and O'Connor, K. F. N.Z. J. Bot. 15: 761-765 (1977); Williams, P. A. et al. N.Z. J. Bot. 16: 255-260 (1978); Williams, P. A. et al. N.Z. J. Bot. 16: 479-498 (1978); Lee, W. G. and Fenner, M. J. Ecol. 77: 704-716 (1989); Payton, I. J. et al. N.Z. J. Bot. 24: 529-537 (1986)].

Flowering is irregular and there are mast years [Connor, H. E. N.Z. J. Bot. 4: 392-397 (1966); Mark, A. F. N.Z. J. Bot. 3: 180-193 (1965), N.Z. J. Bot. 3: 300-319 (1965), Vegetatio 18: 289-306 (1969); Payton, I. J. and Mark, A. F. N.Z. J. Bot. 17: 43-54 (1979); Kelly, D. Trends in ecology and evolution 9: 465-470 (1994); Kelly, D. et al. N.Z. J. Bot. 30: 125-133 (1992); McKone, M. J., Kelly, D. and Lee, W. G. Global Change Biology 4: 591-596 (1998)].

CYTOLOGY

2 n = 6 x = 42 in all 17 species examined: Beuzenberg, E. J. and Hair, J. B. N.Z. J. Bot. 21: 13-20 (1983); Calder, J. W. J. Linn. Soc. Bot. 51: 1-9 (1937); Dawson, M. I. N.Z. J. Bot. 27: 163-165 (1989); just what plants were growing at the Royal Botanic Gardens, Kew, in which Singh, D. N. and Edmonds, M. B. E. Heredity 18: 538-540 (1963) reported 2 n = 12 cannot be determined, but it is unlikely that they were Danthonia flavescens Hook. as was suggested. Somatic chromosome counts of 2 n = 36 by Calder, J. W. J. Linn. Soc. Bot. 51: 1-9 (1937) are unsupported by current counts.

INCERTAE SEDIS

The exact identity of specimens gathered by A. F. Mark and J. A. Wells from Mt Burns, Hunter Mts, Fiordland, at 5400 ft, in May 1967, and described as "Dominating extensive areas above about 4,800 ft, except on exposed ridge crests" (OTA 18879, OTA 18880; duplicate CHR 132494) is somewhat uncertain. They have keeled, flat, prickle-toothed, persistent leaf-blades up to 5 mm wide, on entire, minutely hairy sheaths; the inflorescences of late season origin are glabrous. They are hybridogenous. Similar plants were gathered on Mt Tiriroa by K. Lloyd in 1997.