Re: Brocchinia

Rick Walker (
Mon, 07 Feb 1994 12:12:34 -0800

> >To date all I know is that they are bromeliads and they were added to the
> >carnivorous plant list in 1984.
> Not to *my* list (*because* they are bromeliads)!
> If these were accepted as cp, one would have to accept _Capsella_
> (Brassicaceae), _Pelargonium_, _Geranium_ (Geraniaceae), _Petunia_,
> _Solanum_ (Solanaceae), _Lathraea_ (Scrophulariaceae), _Dipsacus_
> (Dipsacaceae), _Molinia_ (Poaceae), almost *all* Bromeliaceae and Araceae,
> and too many others, too.
> BTW, I do not think that _Roridula_ is carnivorous (even if this is
> included in my list).


What are your criteria for judging carnivory?

I thought the classical criteria (Darwin, Lloyd?) were something like:

1) Attracts prey: (scent, color, nectar, etc)
2) Has specific adaptations to trap prey:
(pitfall, clamshell, flypaper, etc)
3) Has adaptations for utilizing prey
(digestive enzymes, symbiotic fungi, bacteria, etc).

According to these criteria, _Capsella_ would appear be carnivorous.
Its seeds chemically attracts mosquito larvae, traps them in mucilage,
and it can be demonstrated that the seed is beneficially affected by the
absorbed nutrients. Similar arguments can be made for some of the
others on your list, like Bromeliaceae.

Others fail the test: Roridula does not have glandular, digestive
secretions and does not appear to absorb nutrients from prey, _Solanum_
again has sticky hairs, but no direct absorption, etc.

I'd be interested in where you draw the dividing line?