Amaryllis belladonna petal tips
Hannon (Mon, 30 Sep 2013 19:39:55 PDT)

They have been called "cohering keels" and an illustrated article about
them by H. Harold Hume appeared in the Proceedings of the Florida Academy
of Sciences (1: 48-57, 1936). His paper looked at Zephyranthes, Crinum and
a few others.

The idea is that they function like latches and allow the tepals of the
closed flower to expand to full size (or nearly so) before opening, and
allow the protected androecium and gynoecium to grow close to maturity,
until the flower "suddenly" opens when the keels are forced to unlatch
because of the irresistible force of the growing tepals. This effect can be
seen in slow motion photography of flowers opening, depending on the
species.

This feature seems to have received little attention from taxonomists,
which fact Hume remarked upon, but it is certainly an interesting
mechanism. Thanks for sharing the photos!

Dylan

On 30 September 2013 14:11, David Pilling <pbs@pilling.demon.co.uk> wrote:

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"People generally quarrel because they cannot argue."
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