Cleistogamy

Abstract

I SHOULD like to add a few words to the extract from the minutes of the Scientific Committee of the Royal Horticultural Society, quoted in NATURE, November 22, p. 86. The causes of the cleistogamous condition of some of the plants mentioned I would attribute to their stunted habit induced by mowing, coupled with a relatively cold season. For, while some of them, e.g. Cerastium, Montia, and Alchemilla, rarely open their buds, the Veronica, Sagina, and Trifolium, are more inclined to do so, if allowed to grow more vigorously, and if the temperature be higher. Cleistogamy is of course only a relative quality. Thus chickweed and spurry will open their flowers widely in hot weather; but are cleistogamous and abundantly self-fertile all through autumn and winter, if it be mild. With regard to Trifalium subterraneum, as it was about thirty years ago when observed it, I cannot now be certain that it was actually cleistogamous; but it grew with just the same habit as the above, and was most probably self-fertile as they are.