352 Trail -tactions. 



stems creeping beneath the surface. Other plants are quite common — cq.. 

 small tussocks of Poa Colensoi, tufted Danthonia semiannularis, Carex 

 breviculmis, Uncinia rubra, Colohanfhas Billardieri in tiny rosettes which 

 may make small cushions, Ranunculus inultiscapus, Geranium sessilif.orum, 

 Pimelea laevigata var. repens, Epilobiuni elegans, the great bayonets of 

 Aciphylla Colensoi (much less common than formerly), A. squarrosa, Aniso- 

 tome aromatica, Gaultheria antipoda var. depressa, close turf of Coprosma 

 Petriei on stony ground making in places a special " group," and in the 

 most exposed and dry stations yellowish-green cushion 5 cm. in diameter 

 of Colobanthus brevisepalus, Wahlenhergia saxicola, Lagenophora petiolata, 

 Celmisia longifolia, Vittadinia australis, Helichrysum bellidioides, H. fiU- 

 caule, Cotula squalida, Microseris Forsteri, and Taraxacum glabratum. 



**** Subassociations. 

 f Danthonia RaouUi Steppe. 

 This subassociation frequently occupies wide areas. Its presence appears 

 to depend upon increase of altitude, poverty of soil, acid or cold soil, and 

 perhaps exposure to wind ; but the conditions governing its distribution 

 throughout New Zealand have been altogether insufficiently studied. The 

 tussock itself is much taller than that of Poa caespitosa or Festuca rubra 

 var. It is also much less relished by stock, and so its present distribution 

 ma}' not be a natural one. 



ft Danthonia flarescens Steppe. 



This subassociation generally occupies a higher altitude than D. Baoulii 

 or Poa caespitosa steppe. Certain of the higher mountain plants enter 

 into the combination, and the subassociation itself may grade off into fell- 

 field. The dominant species is much relished by sheep, so the true ecology 

 of the subassociation is not easy to determine. 



ttt Dwarf Carmichaelia Steppe. 

 This has been already described. Besides C. Enysii and ('. uniflora, 

 ('. nana is in some places an important member, and the much stouter 

 C, Monroi builds stiff open cushions, its stout woody root descending 

 deeply and its short stiff stems more or less vertical. The low-growing 

 Veronica pimeleoides var. minor grows here and there, a species with small 

 glaucous leaves and blue flowers — a most unusual colour in New Zealand ; 

 and the leafless grey stems of Muehlenbechia ephedroides may lie upon the 

 stony ground, their very much stouter creeping stem hidden beneath the 

 stones. 



tttt '^''•'orf'V' Stcp])c. 



This subassociation consists principally of an extremely dense turf of 

 the small grass Triodia exigua, which spreads most extensively by means 

 of its long much-branching rhizomes, which form eventually a matted 

 tangle. The leaves are very narroM% 2-5 cm. long more or less, filiform, 

 convolute, stift", and almost pungent. StypheUa Fraseri grows through the 

 turf, hugging the ground. Carmichaelia Enysii, C. nana, and Staclchousia 

 minima are, so far as we remember, members of the combination, but un- 

 fortunately our notes are too brief for an accurate, detailed description. 



(e.) Gaya ribifolin Association. 

 On fairly slieltered hillsides, in gullies, on river-terraces, and freipiently 

 where the ground is quite stony, especially in the lower Ashburton Gorge, 



