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Dichogamy May 15th / 64

Common Rhubarb from tall stalks & numerous flowers with white perianths is conspicuous but perhaps not more so than a dock─ it is not fertilised by the wind. Filaments short— pollen moderately coherent— the 3 stigmas capitate— turned almo down almost to base of corolla— the margins seem chiefly penetrated by pollen-tubes. Flowers are incessantly haunted by Diptera if many kinds which suck the nectar secreted round base of ovarium. These flies are dusted with

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pollen. Hence clearly adapted for insects yet on calm fine day I saw, after a blow a cloud of pollen— hence may be aided by the wind & shows means of transition.— I have seen clouds of pollen 2 or 3 times. Twice on same hot day same stalk on a blow emitted clouds of pollen— Certainly good transition state— Stigma never turn up— is bent down to gangway all round base of ovarium — edges of large stigmas fill up nearly whole space & edges are evidently stigmatic.