Date: Thu, 26 Mar 1998 07:44:08 From: SCHLAUER@chemie.uni-wuerzburg.de To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1041$foo@default> Subject: Re: _Drosera burmannii_
Dear Maciei (and all others who have kindly forwarded this message to
the cp list),
> I look for some information about botanic or phytochemical description
> of Drosera burmannii species (from Droseraceae).
The species is described (botanically) in some detail in Diels'
monograph (Pflanzenreich 26, 1906). It occurs in tropical Asia and
Australia. Together with _D. sessilifolia_ (from S America and one
dubious collection from Sierra Leone) it belongs to Thelocalyx, a
distinct group (subgenus in my classification) of rosetted annuals (or
in some cases ?perennials) with pentamerous (an assumedly primitive
condition shared with _Aldrovanda_ and _Dionaea_) ovary and five
styles (the remaining species in the genus having trimerous ovaries
with 3 styles). _D. burmannii_ is one of the species of _Drosera_
with large, "fast" marginal tentacles, the movement of which (induced
by mechanical stimulation) being among the fastest in the genus.
According to Takahashi & Sohma, Thelocalyx is characterized by a
"primitive" pollen type. _D. burmannii_ has 2n=20 chromosomes, which
is not an unusual count for _Drosera_.
In their 1994 paper in Biochem. Syst. Ecol., Culham and Gornall have
identified 7-methyljuglone as the main metabolite of _D. burmannii_.
This is not entirely surprising because Droseraceae (together with a
bunch of other carnivorous plant families) are notorious for their
production of acetogenic naphthoquinones and similar natural products
(cf. CPN 26:34-38, 1997).
Kind regards (also to Prof. Budzianowski)
Jan
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