ABSTRACT
Cephalanthera grandiflora; rostellum aborted; early penetration of the pollen-tubes; case of imperfect self-fertilization; cross-fertilization effected by insects which gnaw the labellum Cephalanthera ensifolia Pogonia Pterostylis and other Australian orchids with the labellum sensitive to a touch Vanilla Sobralia. Cephalanthera grandiflora orchid is remarkable from not possessing a rostellum, which is so eminently characteristic of the order. The anther opens whilst the flower is in bud and partly expels the pollen, which stands in two nearly free upright pillars, each nearly divided longitudinally into halves. The terminal portion of the labellum is frosted with globular papillae of an orange colour, and within the cup there are several transversely wrinkled, longitudinal ridges of a darker orange tint. The early penetration of the stigma by a multitude of pollen-tubes, which were traced far down the stigmatic tissue, apparently gives us another case, like that of the Bee Ophrys, of perpetual self-fertilization.
