Re: NEPENTHES physiology & taxonomy

Jan Schlauer (
Wed, 21 Sep 1994 15:05:14 +0100


>(...) any CP's derive an appreciable
>amount of metabolic energy from their carnivory. Certainly the
>insects etc provide fixed nitrogens and trace elements, but
>is there any real evidence that photosynthesis is not the dominant
>energy source under any conditions?
>-David B

This is a very important point. I have already prepared to post a similar
message. Maybe we should not buy everything from JUNIPER & al.

RE: prey spectra

A recent source is KATO, HOTTA, TAMIN & ITINO:
"Inter- and intra-specific variation in prey assemblages and inhabitant
communities in _Nepenthes_ pitchers in Sumatra"
TROPICAL ZOOLOGY 6:11-25 (1993)

A striking result cited therein is the efficiency of _N.inermis_ (still
under the name of _N.bongso_ sensu TAMIN & HOTTA), which includes
"tourists" (i.e. non-prey) in the first line whereas most other species
studied captured mainly ants.


>I regard this
>forum as a place to discuss the species and their biology, but not the
>nomenclatural minutae, which makes dull reading for the majority of Bulletin
>board readers.

I am sure quite a lot of Bulletin board readers are highly interested how a
monographer of _Nepenthes_ for Flora Malesiana thinks about precision in
nomenclatural minutae.

> I think by and large we are in agreement on what species are present

OK, but it is the (admittedly few) differences which are interesting.

>(...)Nepenthes' evolutionary history. Some species no doubt (APPEAR TO?) form
>related groups:

Let us continue this thread a bit.


I would add _N.muluensis_ and a not yet validated species from Sumatra
("N.adnata" TAMIN & HOTTA, cf. SCHLAUER & NERZ, in press) to this group.
_N.reinwardtiana_ is related but more remotely so, I think this is closer
to _N.gracilis_.


This group should in my opinion include all of DANSER4s Regiae (maybe with
the exception of _N.mollis_) these seem to form a fairly homogeneous clade
by morphological/geographic grouping. BTW, Do you know something about
_N.maxima_ from Siberut (cited in ADAM, WILCOCK and SWAINE)? It seems
unlikely, at least. You should check this when you visit BO. Some specific
(nomenclatural, again...) rearrangements are necessary in this group (e.g.
we do not think DANSER - and almost all subsequent authors - had a correct
impression of _N.stenophylla_ and _N.fallax_, publication in preparation).


"tomentella (Becc.)" (if you want to distinguish it from the Javan taxon, I
would prefer specific rank rather than subspecific) should be added to this
group. I think "N.junghuhnii" (at least the poor material I know about) is
a member of this group (Montanae DANSER), too.


These are so close to each other that they could even be grouped in a
single species (they were so in the past).




Yes, indeed. There is also the _N.neoguineensis_-group which may or may not
be related to this one.

Other groups:

_N.gracillima-sanguinea-macfarlanei_ (rather three prominent "poles" in a
hybrid swarm than separated species).



This group as a whole is certainly not too homogeneous, but some
morphological overlap does exist. _N.ventricosa-burkei_ and _N.bellii_
might be "satellites" or even members of this group (Nobiles/Insignes
DANSER, rearranged).

The Indochina-group _N.anamensis-geoffrayi-kampotiana_ is so tight that
IMHO no species limits can be sustained (publication in preparation).

Well, and then there are the (mostly lowland, mostly widespread, but always
primitive?) species which are difficult to group.

Two rather important questions are still not addressed:

1. Which is the closest (known) relative of _Nepenthes_?
2. How to arrange the groups in terms of evolution and phylogenetic
relationship to each other, i.e. which species are "primitive" and which
are "derived"? How about chorology?

Kind regards