Mt Cavendish rarities

Press, 21 July 1988, Page 12

Mt Cavendish rarities

By I

DERRICK ROONEY

MT CAVENDISH Scenic Reserve, first gazetted in 1911, is one of a number of small reserves along the dry face of the Port Hills, overlooking the Christchurch region and the Plains. It covers an area of 7.5 ha, most of which comprises steep, rocky bluffs, facing north, just above the road. Above the bluffs is a roundish knob which falls steeply to the west and gently to the south and east.

The reserve has quite high scientific values, both botanical and geological. In his detailed survey of the Canterbury reserves (the only such survey published in recent years), G. C. Kelly, Botany Divison, D.5.1.R., described it as including “some of the best examples of lava flow and pyroclastic debris sequences to be seen on the Port Hills, with examples of intrusive dykes, one of which is of textbook clarity.” From a botanical viewpoint, Mt Cavendish contains probably

the best example in any reserve of the indigenous plant communities of dry, north-facing outcrops. The species include one of the most rare plants in the New Zealand flora, the thick-leafed rock fern, Pleurosorus rutifolius.

Another rare species on the Mt Cavendish bluffs is the rock koromiko, Hebe lavaudiana, which is confined to Banks Peninsula where it is found on rocky faces in scattered localities. Prostrate kowhai is the dominant shrub, and it is a host for several uncommon small lianes. These include Scandia Geniculata, one of the few climbing plants in the carrot family; a native convulvulus (C. verecundus), which grows on Banks Peninsula but is seldom seen elsewhere in New Zealand; and a small, blue-green vine, Rhogodia triandra, which reaches its southern limit on the peninsula. Other interesting plants to be

seen in Mt Cavendish reserve include the native leafless clematis, white-flowered native linum, an uncommon rock-fern (Cheilanthes, the necklace fern, and the leafless lawyer-vine.

Kelly described the reserve as “Si particularly useful addition to the Summit Road suite, preserving much of the characteristic flora of the dry rocks.”

Its historical significance must not be overlooked. Along with other reserves on the Summit Road, it was given to the nation by the Morton family as part of the Summit Road concept of a scenic route with a number of protected open spaces for the public to enjoy. "Open spaces” is probably the key phrase. The botanical and geological importance of these reserves was, in general, realised only after they had been set aside for public use and enjoyment.