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1. Composition and Structure.
The number of indigenous species considered true members of the association is 102, representing 74 genera and 33 families. There are
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7 pteridophytes, 30 monocotyledons, and 65 dicotyledons. Of these 53 are more or less common, 40 infrequent or local, and 9 rather rare. There are 17 species of Grramineae, 16 of Compositae, and 13 families are represented by 1 species each.
The growth-forms represented are:—5 small tuberous-rooted summer-green herbs; 13 simple rosette plants; 33 tuft-plants, including 12 tussock or semi-tussock plants; 3 trailing herbs; 36 creeping plants, including 7 turf-forming plants, 16 mat-forming plants; 12 bushy plants, including 4 shrubs and 1 tuft-tree. These may be grouped as herbaceous 77, semi-woody 17, woody 8.
Though the general physiognomy is similar throughout and only one association is recognized, detailed examination shows that the composition varies from place to place. In general Festuca novaezealandiae is dominant over very considerable areas, with Poa caespitosa sub-dominant; but there are also large areas where the relative importance of the two species is reversed, or where the two are present in approximately equal amounts. Abundant members are Agropyron scabrum, its long drooping flowering culms forming in season a striking feature on many slopes, *Agrostis vulgaris, Dichelachne crinita, *Anthoxanthum odoratum, *Rumex Acetosella, Hydrocotyle novaezelandiae var. montana, Nertera dichondraefolia, *Hypochaeris radicata, Helichrysum filicaule, Cotula squalida. Poa Colensoi, Danthonia semi-annularis and D. pilosa, although very common, do not assume the importance or dominance they have in certain low tussock-grassland communities elsewhere. Other very common species are Carex breiviculmis, Luzula campestris vars., Ranunculus multiscapus, Acaena Sanguisorbae vars., especially var. pusilla (but not remarkably aggressive), Geranium sessiliflorum vars., Oxalis corniculata, Epilobium chloraefolium var. verum, Oreomyrrhis andicola var. ramosa, Deyeuxia avenoides var. brachyantha, Wahlenbergia gracilis vars., Celmisia spectabilis, Vittadinia australis var., Gnaphalium collinum, Helichrysum bellidioides, *Trifolium repens, *T. dubium, *Holcus lanatus, *Crepis capillaris, *Cerastium vulgatum.
Often of physiognomic importance are Phormium Colensoi, Cordyline australis, Fuchsia Colensoi, Carmichaelia subulata, this last now closely eaten down. Aciphylla Colensoi is now quite uncommon, odd plants indicating the probable sites of the once striking colonies. Aciphylla squarrosa, now rare except along road-sides, was probably also common, as may have been Angelica montana, now only to be found in places inaccessible to sheep.
On much insolated and wind-bitten slopes the low tussock-grassland may ascend to about 1000 m. altitude, while on steep, shaded spurs tall tussock-grassland may descend to 300 m. Closer examination reveals how surely the composition of the grassland changes in accordance with apparently quite minor variations of slope and aspect. On concave slopes Poa caespitosa at once becomes abundant, with often an increase of Agropyron scabrum and *Agrostis vulgaris. Here also will occur *Holcus lanatus, Hydrocotyle novae-zelandiae var. montana, Chrysobactron Hookeri var. angustifolia, Viola Cunninghamii, Pratia angulata, Microlaena stipoides, Poa Kirkii var., Carex Colensoi, Ranunculus hirtus, Epilobium nerterioides, Anisotome aro-
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matica var., Senecio bellidioides, with perhaps odd tussocks of Danthonia flavescens.
Small steep banks usually show Senecio bellidioides, Viola Cunninghamii, Viola filicaulis, Anisotome aromatica, Asplenium flabelli folium, Lycopodium fastigiatum, in fair quantity.
On flushed ground Juncus polyanthemos* var., Schoenus pauciflorus and Carex ternria form colonies, pure or mixed. Here generally is much Chrysobactron Hookeri var. angustifolia, and with other plants coming in, e.g. Mazus radicans, Oreobolus pectinatus, small areas of bog are developed. On dry concave slopes numerous examples of Cordyline australis may occur, presenting a park-like appearance.
On steeper concave slopes much exposed to wind and sun we have a complete contrast. Where not actually occupied by debris scrub, such slopes present an intermediate character. The grassland is open, Pteridium esculentum is often abundant, with sometimes Hypolepis Millefolium and Paesia scaberula. Very often there is much *Verbascum Thapsus, *Digitalis purpurea and *Cirsium lanceolatum. Odd plants of Discaria toumatou, Muehlenbeckia complexa, Rubus australis, R. cissoides, R. subpauperatus and Coprosma parviflora may be dotted about.
Convex slopes and ridges are characterized by the dominance of Festuca novae-zealandiae, and the presence of much Helichrysum filicaule, Leucopogon Fraseri, Blechnum penna marina and Scleranthus biflorus. Other plants more frequent here are Deyeuxia avenoides var. brachyantha, Triodia pumila, Echinopogon ovatus, Muehlenbeckia axillaris, Halorrhagis procumbens, Vittadinia australis var., Raoulia subsericea and R. Monroi.
Where dry rocky outcrops occur the following are usually met with: Poa Colensoi, Danthonia setifolia, Luzula campestris vars., Colobanthus acicularis, Angelica montana, Wahlenbergia albomarginata, Tillaea Sieberiana, Hebe, amplexicaulis, Coprosma brunnea, Brachycome Sinclairii, with certain of the common grassland plants, e.g. Leucopogon Fraseri, Celmisia spectabilis. Where the rocks are damper and more shaded Hymenophyllum multifidum, Anisotome aromatica vars., and Senecio bellidioides will also be present. At the bases of the rocks, if miniature débris slopes are formed, Rubus spp., Hymenanthera dentata var. alpina and other plants of the débris scrub association may be present.
The larger streams in the grassland have their banks occupied by more or less well-developed gully forest. On the smaller ones this is reduced to a thin shrubby margin with Olearia avicenniaefolia and Hebe salicifolia var. communis predominating. Quite small streams are often marked out by lines of Arundo conspicua, broken by sheets of Carex ternaria and Juncus polyanthemos var., or Schoenus pauciflorus.