Tribe Calypsoeae - The Pollination Biology of North American Orchids: North of Florida and Mexico - page 126

Fig. 6.7 Corallorhiza trifida. ( a ) Flower, front view; ( b ) Column, side view; ( c ) Column, ventral
view; ( d , e ) Column apex, ventral view following loss of anther cap with pollinia in place ( d ) and
with one pollinium on the stigmatic surface ( e ), scale bars = 1 mm. an anther, ca caudicle, cl cli-
nandrum, gr groove, po pollinia, sg stigmatic area, si stipe
Extensive intraspecific variation occurs in flower color (Freudenstein 1997 ). The
sepals and lateral petals are often whitish or greenish, sometimes suffused with red,
purple, or brown, especially near their tips, but in C. striata they are basically
salmon red with distinct purple stripes. The lip is often white, and all perianth parts
may be spotted with purple.
Compatibility and Breeding System
Catling ( 1983 ) reported that individual chasmogamous and cleistogamous plants of
C. odontorhiza from southern Ontario remain constant year after year and that their
flower type is probably genetically determined. He conducted pollination experi-
ments on both types. Chasmogamous plants produced 100% seed set in self-, geito-
nogamous-, and cross-pollination tests but no seeds in tests for autogamy or