280 Transactions. — Botany. 



altogether from that of the tussock meadow, owiug its 

 characteristic stamp to the numerous yellowish-brown (in 

 winter) tufts of Rostkovia gracilis, 28 cm. in height, which 

 form considerable patches, but not appearing as tall as they 

 really are owing to their waving in tlie vvind. Growing side 

 by side with the Bostkovia in large quantities is PlcHrophyUum 

 hookeri, and this, when in flower during the summer, will 

 doubtless be the most striking feature of the formation. Large 

 green cushions of Phyllachne clavigera are everj-where abund- 

 ant, some of them of great size — e.g., 66 cm. x 40 cm. and 

 20 cm. high — the extremities of the shoots rooting in the de- 

 cayed leaves now turned into peat, and which make up the 

 chief bulk of the cushions. Each main shoot of this interesting 

 plant branches near its extremity, giving off several short 

 shoots 1 5 cm. in length, the upper 6 cm. of which are densely 

 clothed with very small imbricating green leaves. These 

 final shoots are all pressed tightly together, and make appa- 

 rently a solid convex mass. The leaves are very thick and 

 coriaceous, expanded at the base, convex on the under (outer) 

 surface, but slightly concave on the lower half of the upper 

 (inner) surface, but flat on its upper half. They are not quite 

 erect, but the globose tips point slightly outwards. This 

 plant, then, is of that typical bog xerophytic form, as pointed 

 out before, common to many New Zealand, Fuegian, and 

 Andean plants, and which reaches its climax in the vegetable 

 sheep of New Zealand, which, however, are not bog-plants, 

 but denizens of sunny alpine rocks. 



Other common members of the Rostkovia formation are 

 Luzula crifiita, Helichrysum prostratum, a species of Carda- 

 7nine spoken of further on, one or two small grasses, Poly- 

 jjodiicm australe pumila, Rammctdus sitbscapostis, Ahrotanella 

 ■ro&'idaris , Ilymenophylluvi midtifidum (the mountain form), 

 while everywhere are mosses, lichens, and, most of all, liver- 

 worts. 



The Rostkovia formation usually occurs among the stony 

 debris at the bases of the cliifs near the summits of the hills. 

 This debris, the result of that weathering which has formed 

 the steep faces of the cliffs, is for the most part mixed to no 

 small extent with the peat which has accumulated from the 

 decay of many generations of plants. Here and there large 

 rocks are lying on the ground covered with crustaceous 

 lichens, white and yellow. In other places are patches of 

 Sphagnum, and water oozes frequently out of the ground and 

 trickles over its surface. 



Where the stony debris has little or no peat mixeii with it 

 spermaphytes are almost absent, but there are numerous 

 lichens and mosses. In such situations, however, here and 

 there are the bright-green rosettes of a species of Cardamine 



