re:Drosera indica structures?

SCHLAUER@chemie.uni-wuerzburg.de
Wed, 4 Dec 1996 07:59:31

Dear Jon,

> I also had a question re. Drosera indica. I just got some plants to grow
> from seed and I'm noticing a yellow powdery sustance growing at the base of
> each leaf. It looks like pollen - is it? I've never seen anything else like
> it on any other plant and it is not a fungus/disease etc. Thanks for any
> feedback.

Is the substance soluble in organic solvents? Does it colour the skin
with a faint blue (please, don't really test that: the dye is
difficult to remove)? Does a spot of the substance blotted on paper
change its colour to red if treated with NH3? If the answers are
"yes" in the cases above, you might have a naphthoquinone (e.g.
plumbagin, droserone or 7-methyljuglone). This would be one of the
rather rare cases in which a quinone crystallizes on a plant surface.
Usually, quinones are stored within the plant tissues.

Kind regards
Jan