notes We have two species of Epipactis in CA. E. gigantea is a native species of wet habitats. This is a non-native, somewhat weedy and smaller-flowered species of drier habitats. Botanist Tom Daniels of the Cal Academy writes (on 4th page of PDF here):
''This species [Epipactis helleborine] is native to Eurasia, but has become established (naturalized) throughout much of North America. It comes up in cultivated/disturbed areas of the county, and along trails in forests.''
Note the lower flower in this photo appears to have a coherent clump of yellowish pollen adhering to the stigmatic area of the column (= 'gynostemium'). It's not clear to me whether that pollen is: 1) a (burst) pollinium from this flower (autogamy); or 2) from another flower on this same plant (geitonogamy); or 3) from a flower on another E. helleborine plant (xenogamy); or 4) if it's pollen from some different species (in which case it would constitute 'pollination interference')?
As far as I can discern, both flowers in the photo appear to still have their 'anther caps' unremoved...so I don't think this is autogamy. (See the labelled images at this link for clarification of 'stigmatic area', 'pollinium', 'anther cap', etc.). Postscript 8/2/21: See Figs. 5G-J on pg. 7 of the paper here for very detailed figures illustrating parts of the gynostemium for Epipactis helleborine. After studying that paper, I think the two flowers in the photo have not had any pollinia removed.
