Re: Plumbago - a close relative to Drosera and Neps

Jan Schlauer (Jan@pbc-ths1.pci.chemie.uni-tuebingen.de)
Sun, 4 Feb 1996 12:55:54 +0100

Dear Fernando,

> While in Europe, I discussed with Jan Schlauer the recent
>publications showing throught DNA sequencing

... AND the common possession of the naphthoquinone plumbagin!...

> that Plumbago is not very
>distant from Drosera and Nepenthes. In fact, someone (I'm almost sure it
>was you Jan) even asked me to send some plants in alcohol, since I have
>them growing in my backyard here in Sao Paulo.

Yes, it was me.

> As soon as I got back to
>Brazil, I went to inspect closely these plants, to see the glandular
>hairs supposedly present on the sepals. Surprisingly, the sticky
>tentacles are very similar to those on Drosophyllum or Drosera

I have told you so, so why were you surprised?

>and I found several small ants trapped on these. Very curious!

Very nice!

In the meanwhile, I have received material of _Plumbago indica_
(=P.coccinea, P.rosea) from the Botanical Garden Wuerzburg. I have examined
the calyx glands of this species and found that they felt sticky but there
were no visible droplets of secretion. Upon microscopical examination of
the emergences supporting the glands I could see that the emergences were
indeed positioned exactly above the longitudinal veins of the sepals BUT
the vascular strand did NOT enter the emergence (opposite to what I had
expected). If the plants you have (_P.auriculata_=P.capensis, I suppose) do
indeed trap insects (what I have suggested to be their function, in order
to prevent crawlers - you wrote "ants" !! - from visiting the flowers), I
suppose you can see secretion droplets. So I would like to examine this
species if it perhaps has vascularized tentacles.

> I've already got the plants in alcohol, I just need to confirm
>before sending them off if it was really you, Jan, who wanted the plants.

Yes, I want them. Thank you very much.

To all:
Any other species of _Plumbago_ cultivated/growing wild anywhere? The
Botanical Garden of Tuebingen has _P.zeylanica_ (closely related to or
perhaps even conspecific with _P.scandens_) but I do not know if it will
survive or even flower. Any observation or material concerning the
glandular emergences on the calyx of _Plumbago_ or _Plumbagella_ would be
appreciated very much. Thank you.

"Plumbago larpentae"=_Ceratostigma plumbaginoides_ and the other species of
_Ceratostigma_ do have plumbagin but they lack glandular hairs so these can
be left out for the moment.

I think little by little we are excavating remnants of remote (early
angiosperm, or at least early cp) evolutionary history...

Kind regards
Jan