I observed something of this kind in Cephalanthera grandiflora.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 2] Reference

By the way, Cephalanthera has single pollen-grains, but this seems to be a case of degradation, for the rostellum is utterly aborted.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 2] Reference

The appearance and similarity of the tissues, etc., at once gives suspicion that the lateral membranes of the clinandrum are the two other and rudimentary anthers, which in Orchis and Cephalanthera, etc., exist as mere papillae, here developed and utilised.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 2] Reference

Cephalanthera, flower.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 2] Reference

Among the most significant endemic plants to be mentioned are a rare and very endangered small tree, Zelkova abelicea, as well as Cephalanthera cucullata, Centaurea baldaccii, Campanula hierapetrae, Bupleurum kakiskalae, Bellevalia brevipedicellata, Astragalus idaeus, Arumpurpureospathum, Anchusa caespitosa, Origanum dictamnus, Orchis prisca, and Onobrychis sphaciotica.    From Wordnik.com.  [Crete Mediterranean forests] Reference