Re: Nepenthes hybrids

Eric Schlosser (
Mon, 9 Oct 1995 15:56:01 CET-1CST

Chris Frazier (E-mail: wrote:

> CPers,
> It is generally stated that all Nepenthes are interfertile and that
> hybrids can be formed between any species. Does anyone know of exceptions
> to this? Is it really true that the most distantly related species
> (whatever they may be) can hybridize as freely as closely related species
> (however this may be measured)? Is it true that species pairs that
> co-occur frequently in nature really haven't developed intrinsic
> reproductive barriers?
> Any anecdotes or information that you have on crosses or failed
> crosses would be greatly appreciated.
> Chris

> I would like to repeat my request for any information concerning
> attempted Nepenthes crosses that didn't work. I don't know whether
> to interperet lack of responses so far as indication that Nepenthes
> species are completely interfertile as far as anyone out there knows
> or if it just reflects the shyness of CP growers to admit their
> crosses failed : ) (Shy folk can send their info to me directly, I
> won't look at the "From:" line).


Maybe it would suffice just to compile a list of what is possible.
At least that makes it easier.

There have been some interesting crossings in the past (Veitch &
Co.,) but also many in recent times (Japan,..).
Although hybrids are not as popular right now as they once were - in
fact they are widely neglected and dumped - it would be nice to see
what has been done and what can be found (maybe like the list of Jan
Schlauer). In this connection it would also be nice if it could
be noted what tendencies species show towards hybridisation.
Hybrids in nature are certainly not as rare as occasionally told, but
without doubt there would be much more of them if there weren't
efficient mechanisms to reduce this.

# _N.x kinabaluensis_ however forms almost pure stands in nature
and seems to behave rather like a species than a hybrid, i.e. it
obviously proliferates without any _N.rajah_ nearby and without much
splitting up its characteristics (as can be seen when only few genes
are considered like flower colour, cf. Mendel).
I wonder if anybody has some experience with F2 Hybrids in culture
although I know chances are small that anybody takes care to grow up
hybrids from seed to flowering size and being as lucky as to have two
of them flowering at the same time and being of different sex.

# Also all Malay spp. seem to hybridize like nuts: (sanguinea,
macfarlanei, gracillima). It is very strange that they could have
evolved into seperate species this way growing on the same mountains,
but maybe it wasn't like this all the time. Human interference has to
be taken into consideration (Malaysians love to cut off mountain tops
and put recreational areas there (casinos, growing strawberries,..)).

# Exceptional hybrids that just drop into my mind are maybe:

ampullaria x mirabilis (N)
clipeata x emayi (C)
rajah x fusca (N)
lowii x edwardsiana (N)
truncata x alata (N)
ventricosa x dubia (C)
hirsuta x veitchii (N)

(C) := cultural hybrid
(N) := natural hybrid

Of course there are a lot more interesting and also very complex
hybrids of very different Nepenthes (N.x coccinea, x Fukakusana,
x prosperity ...).

BTW does anybody know the parentage of N.x souma (a Japanese

Eventually my guess would be that all N.species are highly
interfertile like Sarracenia taking this as a proof that they are
still close, but in progress of divergent evolution.
Though to proof this it would be interesting to know whether
Nepenthes are very similar in their genom (chromosomal numbers).
Drosera (e.g. linearis x rotundifolia) can produce hybrids that are
sterile because they are.

I would also like to know if there are any publications dealing with
what insects pollinate Nepenthes (leading to the question can
insects tell a species (what botanists not always can :) ?) and
in general what are the barriers for reproduction between different
species in nature.
And as a question of practical value, what makes them flower ?

Any suggestions are welcome

Eric Schlosser