OECHID 



and stigmas. The trumpet form of the lip is character 

 istic of many of the most beautiful South American 

 Orchids, as Sobralia, Leelia, Cattleya, etc. In other 

 genera the labellum is variously modified. Sometimes 

 it is small and petal-like, sometimes greatly expanded, 

 forming the most conspicuous part of the flower ( On- 

 cidiuni ti(jriniun,Odontoglossiim Londesboroughiamim). 



ORCHID 



1161 



1563. Selenipedium caudatum. 



In other instances it is almost indescribably transformed 

 (Stanhopea, Gongora). 



In nearly all cases the labellum is provided with raised 

 lines, crests, and markings for guiding the insects. In 

 many genera the base is produced into a sac or spur, 

 which secretes honey, or whose walls contain juices 

 which are sought by insects. In the curious Madagascar 

 Orchid, Angrcecum sesquipedale, the spur attains the 

 astonishing length of 10 or 11 inches (Fig. 1564). 



TJie habit of Orchid plants is almost as varied as that 

 of the flowers themselves. It is dependent upon the 

 mode of life of the plants, which, in this respect, may 

 be divided into three classes, saprophytes, epiphytes, 

 and terrestrial Orchids. True parasites are not known 

 to occur in this family. 



The saprophytic Orchids are the most reduced forms, 

 devoid of chlorophyll, and depending for their carbon 

 food |upon the organic matter of the humus in which 

 they grow. The subterranean stem or rhizome consists 

 of a much-knotted coral-like mass which takes the place 

 of roots. In most species the rhizome has been found 



to be invested with a fungus by means of which organic 

 matter of the humus is absorbed and transformed into 

 compounds available to the plant. The annual shoot is 

 a brownish or yellowish stem bearing a few scales and a 

 simple terminal inflorescence. Few, if any, of these 

 plants are successfully cultivated, as it seems impos- 

 sible to reproduce all the natural conditions. Common 

 examples are the North American Corallorhizas. 



The epiphytic Orchids exhibit the most varied forms. 

 These inhabit branches of trees, dead trunks, and often 

 barren rocks in exposed places. They grow, without 

 exception, in tropical or subtropical countries where a 

 part of the year is iinfavorable to growth. As a result 

 of this, they have developed special food reservoirs, 

 pseudobulbs, terminating each season's growth. In this 

 group there are comparatively few plants of attractive 

 habit. They are generally devoid of graceful foliage, 

 each pseudobulb bearing a few stiff, leathery leaves. The 

 older pseudobulbs become shriveled and leafless, detract- 

 ing from the appearance of the plants, and in Pleione the 

 plants are entirely leafless at the flowering time. In 

 some of these, however, the pseudobulbs are numerous 

 and closely crowded, and retain their foliage, making 

 plants of neat, compact habit (Coelogyne, Miltonia). 



The terrestrial species include some of the largest and 

 most stately Orchids of the tropics as well as most of 

 the Orchids of the temperate zone (Habenaria, Orchis, 

 etc.). Many of these are ornamental even when not in 

 flower. The species of Sobralia are noted for their tall, 

 reed-like stems well clothed with graceful foliage. In 

 the tropics they often form dense thickets from 6-12 ft. 

 in height. Most of the species of Selenipedium also 

 have luxuriant foliage, which is attractive at all times. 



Foliage Plants. The Physurese, a small group of 

 Orchids distributed in tropical Asia and the Malay 

 Islands, with a few spe- 

 cies in Africa and North 

 America, are remarkable 

 for their beautifully 

 variegated leaves (Phy- 

 surus, Anoectochilus). 

 The plants themselves 

 are usually small, with 

 the habit of Goodyera, a 

 North American repre- 

 sentative of the group. 

 Variegated or mottled 

 leaves occur also in 

 some otner groups (Cy- 

 pripedium, Phaleenopsis, 

 and Oncidium). 



Historical Sketch. 

 Species of Orchids have long 

 been known to botanists, but 

 the first plants were introduced 

 into hothouses scarcely over a 

 century ago. Plants were sent 

 by missionaries and officers 

 who visited tropical countries. 

 In 1731, Bletia verecunda was 

 received in England from the 

 West Indies. In 1789. Commo- 

 dore Gardner sent plants otEpi- 

 dendrum fmgrans from the 

 woods of Jamaica. One of 

 these flowered two years after 

 and was the first Orchid figured 

 in the "Botanical Magazine," 



1564. 



Angrraecum 

 sesquipedale. 

 To show very 



long spur. 



plate 152, as E. cochleatum. 

 Phaius grandifolius had been 

 introduced nine years before 

 and the Vanilla was also known 

 in English conservatories. In 

 1807 Martyn's edition of Mil- 

 ler's "Gardeners' Dictionary" 

 enumerated 124 Orchids. 



At first the wants of these 

 plants were little understood, 

 and many perished from irra- 

 tional treatment. But as more species were introduced 

 and their natural climatic conditions became better 

 known the plants were treated in accordance with their 

 requirements. 



