256 
PHARMACEUTICAL BOTANY 
VI. Order Orchidales. — Orchidacetz or Orchid Family . — Perennial 
herbs of terrestrial or terrestrial saprophytic or epiphytic growth, 
having grotesque flowers. Roots fibrous or tuberous often sapro- 
phytic in relation, or aerial and with velamen. Stems and branches 
upright, in epiphytic types often forming pseudobulbs. Leaves 
alternate, entire, parallel-veined, sheathing at base, rarely reduced 
to yellowish or pale scales in saprophytes. Flowers irregular, usu- 
ally attractive, entomophilous, arranged in elongated spikes or 
racemes, trimerous. Sepals, three usually similar; petals three of 
Fig. 127. — Flower of an orchid ( Catlleya sp.). (Gager.) 
which two often resemble sepals, third is variously, often greatly 
modified and fused with two outer petaloid stamens as a labellum 
or lighting-board for insects. Third stamen of outer whorl fertile 
(Orchidece) or a barren knob ( Cypripedice ); pollen of fertile anther ag- 
glutinate as pollinia. Three stamens of inner circle barren and 
petaloid or one absent ( Cypripedice ). Stamens all epigynous and 
often three are fused with the style as gynandrium. Carpels three, 
syncarpous, with inferior, three rarely four, one (usually)-celled ovary. 
Fruit a capsule, three-valved and one-celled. Seeds minute, 
abundant and wind disseminated. 
