Zygopetalum.—Under Zygopetalum, several distinct sub-genera are included. The largest-growing and showiest species include Z. Mackayi, Z. crinitum, and other related species. These should be potted in peat, Sphagnum-moss, and loam fibre in equal proportions, with a sprinkling of leaves, and fine broken crocks added. During the growing season occasional waterings with weak, liquid manure should be given; and, after flowering, a rest with restricted water supply. Those that need repotting should be attended to before growth begins, but they will remain satisfactory for years in the same pots if carefully treated.
There are many hybrids, especially of Z. maxillare, which should be treated like the species. Z. rostratum requires a warm, moist house. The Promenæas include P. stapelioides, P. Rollissoni, and P. xanthina. These should be grown in shallow pans, either for suspending or placing on a shelf near the glass of the roof.
Bollea, Huntleya, Pescatorea, Batemannia, and Warscewiczella.—These are sectional names for a leafy class, with rudimentary pseudo-bulbs. They are frequently mismanaged. The plants should be grown in the potting materials recommended for epiphytal Orchids, and surfaced with Sphagnum-moss. Being evergreen, and with no superabundant vitality, they should be kept moist all the year, but liberally watered when growing. A moist corner of the intermediate house, or warm house, should be selected for them, each plant being raised on an inverted pan or pot. When grown in the warm house, a rest should be given in a cooler house after growth is completed, but the plants must not be dried off. They may be propagated by division. All require shade. Botanically they are placed under Zygopetalum.
CHAPTER XXI
ORCHID HYBRIDS
It is impossible to enumerate the immense number of home-raised hybrids in the scope of this book. It must therefore suffice to name some of the principal genera which have been crossed, and a few of the best hybrids, from the garden point of view.
Too much cannot be said for the absorbing interest of raising hybrid Orchids, which is referred to at length on p. 67.
Brassavola Digbyana has been one of the most satisfactory parents, crossing readily with Cattleya and Lælia, and imparting to the hybrids its large flowers and fringed lip. B. glauca has also been useful. Brasso-Cattleya Digbyano-Mossiæ, "Westonbirt Variety," is illustrated in [Plate V].