RECORD: Darwin, C. R. 1863.01.06-.03.23 & 12.11. Monochætum ensiferum. CUL-DAR205.8.35-36. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 4.2022. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR205.8 contains notes on the genus Monochaetum and other plants.


[35]

Jan. 6 – 1863 Monochætum ensiferum

Worsted means old flower with straight pistil

Thread means young flower with rectangular pistil.

Black pollen of yellow anther

White pollen of crimson anther

once fertilised. – (all young pollen, each day from same flower)

[Table of results]

March 23 Pod, I suppose prematurely dropped, with very many unfertilised seeds with as near as I can class 253 good or nearly good, seeds – White wool.

(copied)

[35v]

Jan 8th I now much suspect that insects in young flower crawl under red anther & in old flower crawl under yellow anther; from pushing them upwards, or on under surface bent causes pollen to be flirted out. Pollen incoherent & I strongly suspect, as insect leaves pollen is flirted on stigma – Insect dusted might carry to other flower some on back – yellow anther much smaller in relation to fertilising in one position only. I could see no nectar in the 8 deep surrounding ovarium, which seem adapted.

The connective projection of red stamen are thick & watery, can insect gnaw them? – Mem. pistil remain for short time rectangular – insect then sucking flower would get back dusted – if in old flower, it crawled in with back to pistil all right, perhaps alighting on connective.

[36]

It is clear to me that in old flower with straight pistil, the stigma is most likely to be fertilised with yellow anther for then are now nearest.

(Dec 11th I compared carefully in young flower pollen of both anthers; plenty in yellow anther, but certainly at least twice as much in crimson & equally mature in both anthers.)

With the little movement by plant gets the anther empty themselves almost entirely by time flower is old. – so incoherent is pollen: in extremity pollen enough does not drop on stigma – The astonishing sharpness of stigma is opposed to wind, looks more like gathering pollen from insects' hairy body. – (Pistil is perfectly straight in bud, & even very slightly bent showing before flower opens.)


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

File last updated 25 September, 2022