ORCHID, iiekid (from Lit. orchis, from Gk. bpx(c, testicle, orchid, so called from the shape of the roots). The common name of members of the family Orchidaccie, which has the most highly organized flowers among monocotyledons. Al though beautiful orchids occur in the temperate regions, such as species of Ilabenaria (rein orchis), Pogonia, Calopogon, Calypso, Cypripe dium (lady's slipper, moccasin-floNN -r), etc:., their chief display is in the tropics. There are more than 400 genera and a conservative estimate puts the nuinber of species at 6000, while those that have been proposed amount to 10,000 or inure. The flowers, hieh may be solitary, racemed. or spiked, are exceedingly irregular, and most elabo rately adapted to the visits of insects, a fact discovered by Sprengel in 1793 and inure widely proved by 1Zobert I:row]] in IS33 and later veri fied in detail by Darwin, g1ftfllcr, Gray, and oth ers. (See PoumxArmx.) The brilliant colora
tion of the flowers, some of which are fragrant, and their bizarre forms have made them mueh prized in hothouse cultivation. The most con spicuous structure of the flower is the so-called labellum or lip, which is one of the three petals. This lip is of the greatest importance in attract ing insects, guiding them to the nectar, the pol len, and the stigma. In most °rebid: it is a con spicuous fiat and more or less pendant organ, hut in Cypripedium (lady's-slipper( it forms a sae which suggests the common name. Another conspicuous feature of the flower is the spur, which is really a prolongation of the base of the Consult: Elson, Orchesdral Instruments and • Their Use (Boston. 1903) : Henderson, The Orchestra and Orchestral Masi(' (New York, I899) : Corder, The Orchrstra and Ilmr to Ti>•ite for It (London, 1896). See INSTRUMENTATION.