Dear M^r Darwin

With regard to cleistogamic flowers of Oxalis: is it quite clear that those which you find in O. sensitiva are cleistogams in the same sense as the late flowers of O. acetosella & Violet?¹

I sh^d. suspect that they are merely arrested or imperfectly developed normal flowers—as you may find in probably many many-flowered inflorescences not of Oxalis only. The species you name is a many-flowered one.² Of course there may subsist some relationship between such so-called arrested or abortive flowers & true cleistogams—but a distinction between them generally speaking is clear. From my own limited experience amongst true cleistogams I sh^d certainly say they are not likely to lend themselves to di- or tri-morphic practices!

The style if present in normal flower is nearly always 0 in true cleistogs. & the stamens anything from 1 anther to nine: Corolla 0 or 1–2 or nine little petals.

However—I fear the Herb^m.—any help we can get out of it would be most unsatisfactory.

It is so rarely, to begin with, that specimens are selected with reference to 2–3-morphism. The only specimens that I remember collected to illustrate this matter are some sent by M. Gibert from the Monte Video Country & these are mostly if not all 1-flow^d. species like O. Acetosella.³ I think it w^d. be very desirable to apply to him specially for flowers in fluid.— I think it possible we may have some in fluid from him at the Museum. I will have enquiry made & let you know if we have.—

Very Sincerely yrs | D. Oliver