THE MONOCOTYLEDOXES 2089 



midal Orchid {Anacamptis pyramidalis). Several have flowers which bear a 

 superficial resemblance to animals and are called after them. Bee Orchid 

 {Ophrys apifera). Butterfly Orchid {Platanthera bifolia), Frog Orchid {Coelo- 

 glossum viride), Fly Orchid {Ophrys insectijera) and Spider Orchid [Ophrys 



Fig. 2025. — Orchis mascula. Early Purple 

 Orchid. Inflorescence. 



sphegodes). Several saprophytic orchids also occur in Britain, Bird's-nest 

 Orchid {Neottia nidus-avis) and Coral Root [Corallorhiza trifida) being the 

 best known. Finally, we may mention Tway-blade {Listera ovata). Lady's 

 Tresses Orchid [Spiranthes spiralis), White Helleborine {Cephalanth^ra 

 darnasonium) and the Lady's Slipper {Cypripedium calceolus), found only 

 in Yorkshire and Durham. 



The plants are always herbaceous with sympodial stems bearing simple 

 leaves, which may be fleshy. In saprophytic forms the leaves are often 

 reduced to scales. The rootstock may be a rhizome or may consist of 

 tuberous roots, which are sometimes formed into compound structures. 



The inflorescence is generally racemose and may be a spike, a raceme 

 or a panicle. Occasionally the flowers are solitary. 



The flowers are often of very beautiful form and colour but occa- 

 sionally small, colourless or brown and inconspicuous. They are either 

 hermaphrodite or unisexual, always zygomorphic and they show many 

 elaborate modifications of form in relation to special insect visitors; in fact 

 the floral parts are so modified that many of them receive special names 

 (Fig. 2026). 



The perianth is epigynous, composed of six segments arranged 



