Flower size is also very variable. Genera other than Dendrobium which have horticultural potential are Acanthephippium papuanum , some of the larger flowered Bulbophyllum, Ascoglossum calopterum , Calanthe engleriana and C. chrysantha , almost all species of Coelogyne , some of the larger flowered species of Diplocaulobium, Dipodium pandanum , Grammatophyllum scriptum and G. papuanum, Macodes sanderiana , Paphiopedilum violascens , all of the species Phaius, Phalaenopsis amabilis var. Paphiopedilum violascens merits a special mention because of the revival of interest in the genus in recent years. The flowers are only moderately attractive for the genus. P. zieckianum and P. wentworthianum are probably synonymous with P. violascens .
Distribution is extremely sporadic.
The vast national heritage of orchid species, particularly of such genera as Paphiopedilum , will, in the near future, need to be protected by farsighted legislation. The increase in cattle raising, with the consequent clearing of large areas of forest for pasture, will be one of the most important factors in destruction of habitats. Use of steel axes has now made it comparatively easy to cut down large trees, often the hosts of many orchids. Before the advent of steel, these were often left standing in the garden areas. Unnecessary clearing and burning is sometimes undertaken.