Date: Tue, 27 Jan 1998 11:03:11 -0000 From: Nigel Hurneyman <nhurneyman@onemeaning.com> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg357$foo@default> Subject: Re: bugs, pygmies
Hi Andy,
Your D scorpioides is entirely normal - in fact it sounds as though you
are taking good care of it.
The reasons were explained to me in a lecture which specifically
discussed Drosera drummondii (now Drosera barbigera). In habitat, the
surface temperature can get to 120F, killing the main stem of upright
pygmy sundews. An inch or so above the sand the temperature is about
20F lower and the dormant top growth can last out until cooler, wetter
times. The top growth will then put out aerial roots which push through
the sand until they hit water (the water table from granite run-offs is
often only an inch below the surface at this time of year). The pygmy
then goes through the normal gemmae/growth/flowering cycle until the
next summer. (Laurent - there are good reasons for not cutting the main
stem in the wild because it supports the live part of the plant in the
cooler air, but I don't see why you shouldn't cut it in cultivation,
other than as a commemoration of the plant's age).
I thought that seed production in pygmies in cultivation was governed by
how close the male and female flower parts are - close together and an
accidental jolt could knock some pollen across. All my smaller, more
primitive plants (occidentalis, pygmaea) readily set seed. However, as
shown in a paper reviewed by Jan in CPN, some pygmies are not
self-compatible (mannii). It would be interesting to know whether this
is a function of how 'unprimitive' the plants are.
My D pulchella are very prolific self-seeders and my D nitidula ssp
allantostigma are vary rare self-seeders. I don't know the chromosome
counts but crosses between the nitula complex and pulchella are
possible. I would have thought that you would be unlikely to get any
hybrids just from the plants being sat next to each other unless you
gave nature a hand with a paintbrush or flying insects had ready access
to both sets of flowers at the same time. However, if I'm wrong, please
can I secure a place high in the queue for spare gemmae of your hybrid!
Regards, NigelH
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