Autumn and winter flowering evergreen and leaf-losing Orchids natives of Asia, Africa and Australasia. The name Calanthe is derived from the Greek kalos, beautiful, and anthos, a flower. Calanthe belongs to the family Orchidaceae.
Leaf-Losing Kinds. Of these the two most 1ffi portant species are C. rosea and C. vestita. The latter has the larger flowers, with usually white segments and the lip divided into three lobes; at the base of the lip there is a yellow or blood-red blotch, the color distinguishing two favorite varieties, luteo-oculata and rubro-oculata. The original species C. rosea and C. vestita, are seldom grown; they have been superseded by hybrids.
The earliest of these hybrids, C. Veitchii, bears forty or more flowers in an inflorescence, the flowers varying in color from soft to deep rose. Numerous other hybrids have since been raised: they include C. bella Harrisii, white; C. William Murray, with deep red lip and rose colored sepals and petals, and C. bella, deep rose.
When to Repot-Suitable Compost. These Orchids require repotting each spring, when fresh growth begins, in a mixture of four parts fibrous loam and one part leaf mold, sand and chopped sphagnum moss. Some growers add dried cow manure. The pots must be well drained. To produce flowers, pseudobulbs formed the previous year are selected and planted individually. The older pseudobulbs (back bulbs) may be used for propagation. If potted and treated in the same way they will produce new pseudobulbs that will bloom the following year.
Summer and Winter Management. After repotting watering must be done carefully, for if the new compost becomes sodden, root action is prevented. When the pots are full of roots, however, water may be given freely and the plants benefit then from weekly applications of dilute liquid fertilizer. When in full growth the plants enjoy abundant heat and a moist atmosphere. Full exposure to light is necessary in the autumn to ripen the pseudobulbs and the plants should then be placed on a shelf or other light place in the greenhouse. As the foliage matures and the flower spikes appear water must again be given, but sparingly at first. After the flower spikes have been cut, the bulbs should be kept quite dry, in a temperature of 60 degrees, until fresh growth begins.
Evergreen Calanthes. These include tropical kinds that require essentially the same conditions as the leaf-losing kinds discussed above except that they are not dried off during the winter. At that season, however, the compost is kept some what drier than it is from spring through fall. Among the evergreens are also some natives of Japan that can be grown permanently outdoors in California and in other mild climates. The evergreen kinds require a compost similar to that used for the leaf-losing Calanthes. The plants must be kept moist throughout the year and in winter the minimum temperature should be maintained at 60 degrees.