Pleione D.Don is an Asian mostly terrestrial genus in the Orchidaceae family of about 22 species, which is closely related to Coelogyne and Bletilla. Most species flower in spring after a cool (5°Celsius or less) and dry dormancy, usually before growing new roots. The few fall flowering species and hybrids need warmer winter temperatures and may not go completely dormant. All sprout from annual spongy pseudobulbs formed from last years flower stems. Several species, forms and hybrids are common in trade. Vegetative propagation is relatively easy, since strong plants may also sprout several bulbils at the top of the dying last years pseudobulb, which can be grown to flowering size in 4-5 years.
For the spring species, the time of flowering is strongly dependent on the winter temperatures. Plants stored in typical European basement temperatures (8-10 °C) may start flowering in February, while consequent barely frost free storage will place the main flowering time in April. The plants seem to keep record of some sort of "heat sum", as Martin Bohnet reports plants that have been received in December and stored together after that, had totally different flowering times in that first season, depending on the source.
Photographs of seed pods and seeds by David Pilling. Photo 3 is 10 mm wide, 4-6 are 1 mm. The photos were taken in 2019 of seed pods that grew in 2018.
Photographs of pseudobulbs by David Pilling.
Pleione chunii C.L.Tso, originating from southern China and flowering in spring, is sometimes treated as a subspecies of Pleione hookeriana, but current consent (2021) is to treat it as separate species. Color forms range from white to pale pink with yellow and orange lip markings. The most distinguishable feature are the ridges on the lip which are very finely divided in this species, almost giving the impression of an iris beard. Photos by Martin Bohnet.
Pleione formosana Hayata is native to Taiwan and southern China. It is the most commonly cultivated Pleione, resulting in the common name "windowsill orchid". It can take some frost but needs protection from winter wet, so pot culture is the preferred way of growing them in most climates. A popular range of cultivars is named after Italian composers. Color forms range from white with only minor yellow traces in the lip to rose and lavender shades and prominent darker lip patterns.
Pleione limprichtii Schltr. is is a somewhat smaller Pleione from central Sichuan (China), colored bright pink and no trace of yellow on the lip. It is an easy, undemanding beginner species. Pictures of a plant grown by Martin Bohnet.
Pleione praecox (Sm.) D.Don. is a fall flowering species from warmer parts of western central Himalaya to southern Yunnan, which may keep its leaves until after flowering, but often does not in culture. It likes a winter temperature of 10 to 15 °C and should not be too dry during this time. This species has flattened, spotted pseudobulbs and emits a delicately sweet scent when in flower. Pictures of plants grown by Martin Bohnet.
Pleione species have been heavily hybridized, and some of the more than 400 grexes registered at the Royal Horticultural Society trace back 6 generations to the pure species. Hybrids are often more vigorous than their parents and in few cases even expand flowering times, as there are a few winter flowering hybrids from crossing spring and fall species. Some very active hybridizers can be recognized by their naming scheme, like Cumbleton (primates) or Butterfield (volcanoes).
Pleione 'Follifoot', a third generation hybrid registered by Harberd in 1998 has, for a hybrid, rather small but intensely colored flowers.
Pleione 'Mandrill', is a primary hybrid of fall-flowering Pleione praecox and spring flowering Pleione yuannensis, and as such has nearly no dormancy period, as flowers sprout shortly after the leaves are shed. It grows through winter, so it needs higher temperatures of about 10 to 15 °C during this phase. While the praecox parent dominates the growth pattern, the prominent spots on pseudobulbs and stems of those are barely recognizeable on the hybrid. Photos show a plant cultivated by Martin Bohnet.
Pleione 'Marmoset', a Cumbleton registration made in 2010, is another winter flowering hybrid, with an intensely colored lip, giving away the Pleione maculata seed parent. Seed parent from the spring part of the genus is 'Piton' (P. formosana x P. yuannensis)
Pleione 'Santorini' (Butterfield, 1991) is a pale lilac, large flowered hybrid with a prominent red pattern on the lip, hinting at the P. coronaria parent.
Pleione 'Sifaka' is, as the primate name (Sifakas are a genus of Lemurs from Madagascar) implies, a hybrid registered by Paul Cumbleton in 2005. It combines the growability of Pleione formosana and P. yuannensis, the ancestors of the seed parent, with the yellow of the more capricious P. forrestii. In the petals, yellow and pink overlap to form a delicate shade of apricot.
Pleione 'Tongariro' is a rather big hybrid Pleione with intense magenta-pink flowers and red lip markings. The leaves are virtually absent during flowering. Its parents are Pleione pleionoides and the primary hybrid 'Versailles', which is Pleione formosana x Pleione limprichtii.