Friday, October 17, 2008

Phalaenopsis

Phalaenopsis is a genus of approximately 60 species of . The abbreviation in the horticultural trade is Phal. Phalaenopsis is one of the most popular orchids in the trade, through the development of many .

Description



The generic name means "Phalaen-like" and is probably a reference to the genus ''Phalaena'', the name given by Carolus Linnaeus to a group of large moths; the flowers of some species supposedly resemble moths in flight. For this reason, the species are sometimes called Moth orchids.

They are native throughout southeast Asia from the mountains to the islands of Polillo and Palawan of the Philippines and northern Australia. Orchid Island off Taiwan is named after this orchid. Little is known about their habitat and their ecology in nature since little field research has been done in the last decades.


Most are shade plants; a few are lithophytes. In the wild they are typically found below the canopies of moist and humid lowland forests, protected against direct sunlight, but equally in seasonally dry or cool environments. The species have adapted individually to these three habitats.

''Phalaenopsis'' shows a monopodial growth habit. An erect growing rhizome produces from the top one or two alternate, thick and fleshy, elliptical a year. The older, basal leaves drop off at the same rate. The plant retains in this way four to five leaves. If very healthy, they can have up to ten or more leaves. They have no pseudobulbs. The raceme appears from the between the leaves. They bloom in their full glory for several weeks. If kept in the home, they usually last two to three months.

Some ''Phalaenopsis'' species in Malaysia are known to use subtle weather cues to coordinate mass flowering.

Classification



The species can be classified into two groups :
*A group with a long, branched inflorescence and large, almost round flowers with rose or white tints.
*A group with short stems and less rounded, waxy flowers with more pronounced colors.
In terms of particular lifeform terminology, one can also characterize these plants as hemicryptophyte or chamerophyte :
hemicryptophyte : biennial or perennial plants with herbaceous stems. These stems die off after the growing season, while the shoots survive at soil level. The resting buds are just above or below soil level.
chamaephyte : low-growing plants with herbaceous and/or woody stems, that persist for several years. Their buds are on soil level or just above; but never above 50 cm.

The genera ''Doritis'' Lindl. and ''Kingidium'' P.F.Hunt are now included in ''Phalaneopsis'', based on DNA-evidence . However this is not implicitly accepted by every specialist in this field.

Intensive cross-fertilization has produced a great number of in all colors and variations. These are usually more adaptable to artificial conditions than their botanical ancestors. Most are hybrids of ''Phalaenopsis amabilis'' with ''Phalaenopsis schilleriana'' or ''Phalaenopsis stuartiana''.

Species



*''Phalaenopsis amabilis''
**''Phalaenopsis amabilis'' subsp. ''amabilis'' .
**''Phalaenopsis amabilis'' subsp. ''moluccana'' .
**''Phalaenopsis amabilis'' subsp. ''rosenstromii'' .
*''Phalaenopsis amboinensis'' .
**''Phalaenopsis amboinensis'' var. ''amboinensis'' .
**''Phalaenopsis amboinensis'' var. ''flavida''
*''Phalaenopsis aphrodite'' .
**''Phalaenopsis aphrodite'' subsp. ''aphrodite'' .
**''Phalaenopsis aphrodite'' subsp. ''formosana'' .
*''Phalaenopsis appendiculata'' .
*''Phalaenopsis bastianii'' .
*''Phalaenopsis bellina'' .
*''Phalaenopsis borneensis'' .
*''Phalaenopsis braceana'' .
*''Phalaenopsis buyssoniana'' .
*''Phalaenopsis celebensis'' .
*''Phalaenopsis chibae'' .

*''Phalaenopsis cochlearis'' .
*''Phalaenopsis corningiana'' .
*''Phalaenopsis cornu-cervi'' .
*''Phalaenopsis deliciosa'' .
**''Phalaenopsis deliciosa'' subsp. ''deliciosa'' (Indian subcontinent to Malesia
**''Phalaenopsis deliciosa'' subsp. ''hookeriana'' .
*''Phalaenopsis dowery?nsis'' .
*''Phalaenopsis equestris'' .
*''Phalaenopsis fasciata'' .
*''Phalaenopsis fimbriata'' .
*''Phalaenopsis floresensis'' .
*''Phalaenopsis fuscata''
*''Phalaenopsis gibbosa'' .
*''Phalaenopsis gigantea'' .
*''Phalaenopsis hainanensis'' .
*''Phalaenopsis hieroglyphica'' .
*''Phalaenopsis honghenensis'' .
*''Phalaenopsis inscriptiosinensis'' .
*''Phalaenopsis viridis'' .
*''Phalaenopsis wilsonii'' .
*''Phalaenopsis zebrina'' .

Natural hybrids



*''Phalaenopsis × amphitrita'' .
*''Phalaenopsis × gersenii'' .
*''Phalaenopsis × intermedia''
*''Phalaenopsis × leucorrhoda'' .
*''Phalaenopsis × singuliflora'' .
*''Phalaenopsis × veitchiana'' .

Intergeneric hybrids


x''Aeridopsis''
x''Arachnopsis''
x''Asconopsis''
x''Beardara''
x''Bogardara''
x''Bokchoonara''
x''Cleisonopsis''
x''Devereuxara''
x''Diplonopsis''
x''Doriellaopsis''
x''Doritaenopsis''
x''Dresslerara''
x''Edeara''
x''Ernestara''
x''Eurynopsis''
x''Hagerara''
x''Hausermannara''
x''Himoriara''
x''Isaoara''
x''Laycockara''
x''Lichtara''
x''Luinopsis''
x''Lutherara''
x''Macekara''
x''Meechaiara''
x''Moirara''
x''Nakagawaara''
x''Owensara''
x''Parnataara''
x''Paulara''
x''Pepeara''
x''Phalaerianda''
x''Phalandopsis''
x''Phalanetia''
x''Phaliella''
x''Pooleara''
x''Renanthopsis''
x''Rhynchonopsis''
x''Rhyndoropsis''
x''Richardmizutaara''
x''Roseara''
x''Sappanara''
x''Sarconopsis''
x''Sidranara''
x''Sladeara''
x''Stamariaara''
x''Sutingara''
x''Trautara''
x''Trevorara''
x''Trichonopsis''
x''Uptonara''
x''Vandaenopsis''
x''Vandewegheara''
x''Yapara''
x''Yeepengara''
There is no true intergeneric hybrid between ''Phalaenopsis'' and the closely related ''Paraphalaenopsis''. However, according to the , there is a grex . ''Phalphalaenopsis'' Doris Thornton is currently the one and only registered grex that represents a cross between a ''Paraphalaenopsis'' and a ''Phalaenopsis'' . Therefore, strictly speaking, the genetic barrier between these two closely related genera has not been crossed. But, since there are only very few true ''Phalaenopsis'' species in cultivation , the possibility of a true intergeneric hybrid is not to be excluded.

Post-pollination changes in ''Phalaenopsis'' orchids


''Phalaenopsis'' are not only outstanding in their beauty, but also unique in that in some species, the flowers turn into green leaves after pollination. As in many other plants, the petals of the orchid flowers serve to attract pollinating insects and protect essential organs. Following pollination, petals will usually undergo senescence because it is metabolically expensive to maintain them. In many ''Phalaenopsis'' species such as ''P.violacea'', the petals and sepals find new uses following pollination and thus escaping programmed cell death. By inducing the formation of chloroplasts, they turn green, become fleshy and apparently start to photosynthesize, just like leaves.

Growing ''Phalaenopsis''



''Phalaenopsis'' are among the most popular orchids sold as potted plants owing to the ease of propagation and flowering under artificial conditions. They were among the first tropical orchids in collections. Since the advent of the tetrapoloid hybrid ''Phalaenopsis'' Doris, they have become extremely easy to grow and flower in the home, as long as some care is taken to provide them with conditions that approximate their native habitats. Their production has become a commercial industry.

In nature, they are typically fond of warm temperatures , but are adaptable to conditions more comfortable for human habitation in temperate zones ; at temperatures below 18 °C watering should be reduced to avoid the risk of root rot. ''Phalaenopsis'' requires high humidity and low light of 12,000 to 20,000 lux. Flowering is triggered by a night-time drop in temperature of around 5 to 6 degrees over 2 to 4 consecutive weeks, usually in the fall, and a day-time drop in temperature to below 29 °C.

''Phalaenopsis'' prefer to be potted in osmunda fiber , a nearly ideal medium, but this has become expensive. More usual now is fir bark, which is more free-draining than sphagnum moss. Keep them in pots with a lot of drainage. One of the common blunders that new growers make is to rot the roots. Overwatering and poor drainage cause the roots to deteriorate, therefore killing the plant. The safest thing to do is to water when you feel the potting medium and find it is dry through and through.

Light is vital to the well-being of the ''Phalaenopsis'' orchid. Keep it in indirect light near a southern window. Be sure the sun does not directly reach the leaves, which will cause burning and unaesthetic brown marks. If the leaf feels hot to the touch, move it away immediately! On the other hand, phalaenopsis grown in poor dark areas tend to grow floppy dark green leaves and rarely flower.

''Phalaenopsis'' roots are quite thick, and the green point at the ends signifies that the root is actively growing. It is okay for them to climb out of the pots. Keep the plant fertilized with a 1/4 diluted strength balanced fertilizer three times out of four waterings.

The flower spikes appear from the pockets near the base of each leaf. The first sign is a light green "mitten-like" object that protrudes from the leaf tissue. In about three months, the spike elongates until it begins to swell fat buds. The buds will thus bloom. Usually you can tell what color the ''Phalaenopsis'' is by looking at the bud color. After
the flowers fade, some people prefer to cut the spike above the highest node . This may produce another flower spike or more rarely a keiki .

Using two ''Phalaenopsis'' clones, Matthew G. Blanchard and Erik S. Runkle established that, other culture conditions being optimal, flower initiation is controlled by daytime temperatures declining below 27°C, with a definite inhibition of flowering at temperatures exceeding 29°C. The long-held traditional belief that reduced evening temperatures control flower initiation in ''Phalaenopsis'' appears to be false.

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