ORCHIDACEAE. 67 



91. OLSYNIUM. 



Very similar to Sisyrinchium but the filaments united only at 

 the base and the flowers never blue. 



Olsynium grandiflorum (Dougl.) Raf. Stems mostly solitary, 15-30 cm. 

 tall, compressed; roots fascicled, stout; leaf-blades 5-10 cm. long, erect, shorter 

 than the sheaths; flowers 1-4, the pedicels shorter than the largest bract; 

 perianth-segments reddish-purple, broadly lanceolate, acuminate, 15-18 mm. 

 long; filaments broad at the base, shorter than the 3-cleft style. Very common. 



Family 23. ORCHIDACEAE. Orchid Family. 



Perennial herbs, with corms, bulbs or tubers; leaves entire, 

 sheathing, sometimes reduced to scales; flowers perfect, irregular, 

 bracted, solitary, spiked or racemed; perianth superior, of 6 

 segments, the three outer (sepals) alike or nearly so; two of the 

 inner ones (petals) lateral, alike; the third inner one (lip) dis- 

 similar, often markedly so, usually larger, often spurred, some- 

 times inferior by the twisting of the ovary or pedicel; stamens 

 variously united with the style into an unsymmetrical column; 

 anther one (sometimes two) ; pollen more or less coherent into 

 masses (pollinia); ovary inferior, usually long and twisted, 

 3-angled, 1-celled; ovules numerous on three parietal placentae; 

 seeds numerous; endosperm none. 



Perfect anthers 2; lip large, sac-like. 92. Cypripedium, 68.. 



Perfect anther 1. 



Plant saprophytic, without green herbage. 



Flowers spurred, reddish or white. 93. Corallorhiza, 68. 



Flowers spurless, white. 94. Cephalanthera, 69;. 



Plants with ordinary green herbage. 



Flower and leaf solitary; plant bulbous. 95. Cytherea, 69. 



Flowers several-many in racemes. 



Leaves only two. 96. Ophrys 69. 



Leaves more than two. 



Flowers each with a distinct spur. 

 Leaves several, cauline, gradu- 

 ally reduced upwards. 97. Limnorchis, 70. 

 Leaves two, basal; cauline re- 

 duced to bracts. 

 Lateral sepals adnate to the 



base of the lip. 98. Piperia, 70. 



Lateral sepals free. 99. Lysias, 71. 



Flowers spurless, the lip at most 

 saccate. 

 Lip with 2 callosities at base; 

 flowers spirally arranged in a 

 dense spike. 100. Iridium, 71. 



Lip without basal callosities. 



Leaves white-reticulated. 101. Peramium, 71. 

 Leaves green. 102. Epipactis, 72. 



