MISTLETOES, NEW ZEALAND
Plants of the mistletoe family or Loranthaceae are found mainly in tropical countries but some occur in temperate regions of both hemispheres. They are all partial parasites – they depend partly on other plants, known as the hosts, for their supply of water and mineral salts but have green leaves in which food is manufactured. There are few more showy sights in New Zealand than the brilliant scarlet flowers of Elytranthe colensoi or E. tetrapetala perched high up in the sombre green southern beech (Nothofagus).
Altogether there are four genera of the mistletoe family in New Zealand. Korthalsella has two species, both small and leafless and with minute flowers. They are not easy to find and parasitise such shrubs as Coprosma spp., Dracophyllum spp., tea tree, etc. Elytranthe has 50 species altogether, spread throughout India, Malaya, Polynesia, and Australia. There are four species in New Zealand and all are endemic. Besides the two scarlet-flowered ones given above, the species E. flavida has yellow flowers. It is found on southern beech trees. Leaves are ovate to elliptic and, according to the species, vary from one half to 3 in. long.
Two other genera have each a single species in this country. Loranthus is a fairly large tropical and subtropical genus of some 550 species. The one New Zealand plant, L. micranthus, is endemic. It has oblong leaves usually about 2 in. long, small flowers, and small yellowish berries which are readily eaten by birds. It is widespread throughout the country on a number of hosts, mainly native shrubs and some introduced trees, including fruit trees. Tupeia antarctica is the only species in the genus and is endemic to New Zealand. It is found as a parasite mainly on Neopanax and, in the north, on tarata, Pittosporum eugenioides.
by Alec Lindsay Poole, M.SC., B.FOR.SC., F.R.S.N.Z., Director-General of Forests, Wellington.