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floral characters, the number and density (number of flowers/inflorescence length)
of open flowers per inflorescence. For inflorescences of equal size, the number of
pollinia exported (male function) always exceeded the number imported with a loss
OFABOUTOFTHEPOLLINIAFROMTHEPOPULATION0OLLENIMPORTBYITSELFISCONSID-
ered an unreliable measure of female function, which is better based on seed pro-
duction (Stephenson 1981 ; Bell 1985 ). The latter was not examined in this study,
but according to Bell ( 1985 ), seed production in xenogamous, hermaphroditic flow-
ERINGPLANTSISNOTCLOSELYRELATEDTOSECONDARYmORALCHARACTERS!CCORDINGLY0IPER
and Waite ( 1988 ) believe that the evolution of secondary floral characters in E. hel-
leborine has been a product of selection for higher rates of pollen export. A more
recent study on Epipactis appears to support this conclusion. Ehlers et al. ( 2002 )
found that an increase in flower number enhanced pollinia removal more than fruit
set and also considered the evolution of large inflorescences in Epipactis to likely be
more closely related to selection on male function than female function (e.g.,
Chaplin and Walker 1982 ; Vaughton and Ramsey 1988 ; Emms et al. 1997 0ICKERING
2000 ). Firmage and Cole ( 1988 ) reported a similar relationship for Calopogon
tuberosus. However, Snow and Whigham ( 1989 ) found no differential effect of
inflorescence size on male and female reproductive success in T. discolor , and
according to Tremblay et al. ( 2005 ), a similar parallel response may be true of many
other orchids as well.
Although Light and MacConaill ( 1990 ) reported that fruit set in E. helleborine
was generally high, they found that herbivory, disease, and weather conditions could
significantly reduce the number of capsules that reached dehiscence. These authors
specifically mentioned small animal herbivores as a problem in Quebec, and Mousley
( 1927 ), based on studies in the same province, noted that larvae of Spilosoma virgi-
nica (Fabricus) (yellow, wooly-bear moth) were significant predators on the leaves
of this species.
Additional Species of Epipactis
Epipactis atrorubens (Hoffman ex Bernhardi) Besser, a native of Europe and Asia
with vanilla scented, reddish-purple flowers, is represented in North America by a
small, naturalized population in northern Vermont (Mousley 1927 ; Brown and
Argus 2002 ). Its survival here and elsewhere may be heavily dependent on connec-
tions to tree ectomycorrhizae (Gebauer and Meyer 2003 ).
All studies on its pollination have been conducted in Europe. Contrary to East
( 1940 ) and Tremblay et al. ( 2005 ), E. atrorubens is clearly self-compatible. Hagerup
( 1952 ) reported a predominance of bud autogamy in Denmark, but Sundermann
( 1975 ), Richards ( 1982 ), and Talalaj and Brzosko ( 2008 ) found it to be chiefly alloga-
mous elsewhere. Nectar is produced on the hypochile and is accessible to almost any
insect. Wiefelsputz ( 1970 ) and Robatsch ( 1983 ) suggested that the floral coloration
and scent are likely to attract bumblebees and honeybees, and Talalaj and Brzosko
( 2008 ) found bumblebees ( Bombus sp.) to be the primary visitors. Voth ( 1982, 1988 )
and I. Muller ( 1988 ) reported bumblebees, wasps, and honeybees as pollinators.
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