>Sorry all you listeners who are fed up with all this stuff and
>who have to pay their mailbox bitwise, but there are obviously some
>(strange people!) who want to read it. Maybe we should create a sub-
>list "cp_jans_weird_views"?
Why only your weird views?! I should make an oposing sublist to
compete with yours called "cp_fernando's_weirder_views"!! Anyways, be
ready for another VERY long mail! Unfortunately for many of you, a few
have mailed me asking to keep this thread open. It's true!!
>Interesting idea, indeed. The only present representatives of
>Subgen.Drosera in or near the range of Lasiocephala are Prolifera,
>Arachnopus, and _D.spatulata_ (+ _D.rotundifolia_ in N.Guin, but
>this came rather certainly after Lasiocephala). Can you imagine
You forgot D.neocaledonica.
>a descent of Lasiocephala from one of the precursors of these? I have
>never considered this possibility but it may be worth a thought.
I guess we have to try to guess at what stage of development
Drosera were when Australia began drifting north, its climate began
changing, and the Drosera there present began adapting to the new
conditions and slowly becoming what we know today as the weird taxa in
Australia. Is there any Drosera pollen fossil from this period which
matches any of the existing Subgen.Drosera? Or are they of a more
primitive type?
>I think that the basal bifurcation of the styles in Lasiocephala
>and all representatives of Subgen.Drosera is a synapomorphy of these
>two subgenera. I.e. they are IMHO younger than those "primitive"
>species with basally undivided styles (Thelocalyx, Arcturia,
>Stelogyne, Meristocaulis, Regiae). Bryastrum has undivided styles,
>while it could IMHO still have arisen from a primitive stock which
>has also led to other groups which are nowadays exclusively
>represented by taxa with divided styles (I can not think of a better
>candidate than Lasiocephala here, but perhaps you have another idea?).
I don't know if we can say that they styles in Lasiocephala are
divided near the base in the same way as those of Subgen.Drosera. Looking
at the drawings in Lowrie's latest article on petiolaris-complex taxa, the
first division seems to occur halfway or 1/3 of the way up the styles,
followed by numerous other divisions. I don't know about the other species
in this group, but I believe it must be similar. Diels mentions
bifurcations 'near' the base for D.petiolaris, the 'legs' being
afterwards divided into 2 or more parts.
To me this is rather dubious, with 2 possible interpretations.
Maybe the common ancestor of Lasiocephala had 3 undivided styles, as in
Subgen.Meristocaulis, which began splitting at the apex. In time the
divisions increased in number and moved down along the style. Or maybe
the ancestor had basal bifurcations, as in Subgen.Drosera, which moved
upwards along the styles and branched a few more times.
For D.banksii Diels says the styles are bipartite at the base and
that the legs are trifid below middle, which me may take as an indication
that the latter of the 2 assumptions above may be the true one, but we
can't be sure. Maybe D.banksii is a recent step in the evolution of this
group and not an old one.
>> that in several other groups, including more
>> "advanced" ones, we find 3 styles which are only divided near the top,
>> and not at the base.
>
>Which group do you mean?
I was referring to some from Ergaleium and I thought Phycopsis
too, but now I can't make out from Diels' if they are bifurcated from
the base or not. And this might be aplicable to Lasiocephala, depending on
where the bifurcations originated and when (from which group).
>I would guess Diels but have to check it. At least I have reserved a
>place in the primitive corner for Stelogyne. No problem to shift it
>further "downwards". Thanks for highlighting this!
Does anyone out there have a D.hamiltonii in flower at the
moment or will have soon????? It apparently does have 3 carpels though, as
do all other Drosera except Subgen.Thelocalyx. So the presence of 5
styles, if confirmed, could still be a synapomorphic characteristic as
that found in Lamprolepis.
>_D.acaulis_, _D.felix_, and _D.meristocaulis_ should be grouped
>together *just* because they have a reduced peduncle? Once again: Do
>not disregard style morphology! It is *essential* in the infrageneric
>classification of _Drosera_.
That's not what I'm saying Jan, I'm just trying to show that there
are a few intermediate characteristics present in these taxa between those
of subgen.Drosera and Subgen.Meristocaulis
>Thelocalyx also has a distinctly primitive pollen type (so has
>allegedly Arcturia). The tree by Takahashi and Sohma is a hypothesis
>based *only* on pollen morphology. Other characters indicate a (only
>slightly) different sequence of events. Still I think the
>palynological data are very important here (they are useless at the
>level of Subgen.Drosera, Bryastrum, Ergaleium & al. because pollen
>types 7-8 are ubiquitous there).
OK, so we could possibly just have a bad interpretation of the
evolution of the different pollen types. This could easily explain the
basal position os Thelocalyx instead of Regiae.
>> I agree flower color is weak, but you cut out my other comment on
>> the erect X ascending scapes.
>
>Sorry!
No need to say you're sorry! 8-P
>I only have no comment on this. Is it constant?
Oof! You got me there! I can't really say except for the
D.burmanni form I cultivated, which I clearly remember as having had a
nice big curve at the base of the scapes. I guess we have to ask everyone
else out there who is cultivating these weird forms of D.burmanni if
their plants have erect or ascending scapes. Or even Isao himself who's
plants I saw and who is out there too (hi Isao!).
As for D.sessilifolia, according to my memory, to St.Hil., and to
my friend Tania's thesis, it is always erect.
>Interesting. This would be the first amphi-pacific species in
>_Drosera_. Still the plants should be kept separate at some rank
>because the disjunction is probably an old one.
Just because Thelocalyx is an ancient group doesn't mean that the
disjunction between both species itself is old.
>I think that this has at least created 2 homogeneous sects., viz.
>Ptycnostigma (with the "primitive end") and Drosera (with all the
>apparently more "advanced" members). I am not entirely
>sure about _D.dielsiana_, however. It may have arisen by
>introgression of the "primitive" _D.burkeana_ into the "advanced"
>_D.aliciae/natalensis_ complex. _D.collinsiae_ may be another such
>example. But as even intergeneric hybrids are known in the plant
>kingdom, such phenomena do not necessarily invalidate my concept.
Yes this is a problem, where do you put these hybrids. And there
is also D.anglica in this mess.
>The problems in Oosperma (the trash can for all non-Ptycnostigma &
>non-Drosera taxa) may necessitate further subdivision but this
>should only be done after further study (as it would otherwise only
>add confusion to the names).
OK, so you at least believe that Sect.Drosera is more or less
homogeneous. So the big problem in your opinion is Sect.Oosperma and
Ptycnostygma, right?
>But you still see the difference between _D.chrysolepis_
>and _D.villosa_, even if you use my key, don't you?
Yes, yes, your key still works fine. I'm just being a
perfectionist like you Jan!
>> I'm looking at
>> Allen's book now and though there are several similarities between his
>> D.ericksonae and D.nitidula, the styles of the former are really very
>> unique. If that is the true D.omissa Diels, than maybe that's how it
>> should remain, and not among the other taxa considered D.nitidula by
>> Allen in his book.
>
>Maybe. But Allen Lowrie himself has decided to reduce Diels' name in
>rank.
That's because he had the wrong plant and that's why he put his
D.ericksonae as a separate species.
>> And since when do the 2 taxa have to be sympatric along their
>> whole ranges to be varieties and not subspecies? By what I know, if 2 taxa
>> occur together in at least one site, that's enough to put them as var.
>
>Not necessarily. In _Sarracenia purpurea_ there is also a gradual
>transition between the two subspp.
Well in this genus everything seems to be subsp. and not variety.
I'm talking about Drosera, where you have taken the first step to the
application of both ranks with the distinction between sympatry and
allopatry.
>It is not the number but rather the geographic pattern. The
>geographic distribution pattern of _D.peltata subsp.auriculata_
>suggests allopatric speciation (in the E AU part of the range of
>_D.peltata_).
You can only really affirm this because D.peltata happens to have
a very extensive range, but you can't say whether it and D.auriculata
originated in W. or E.Australia. I think it is very important to remember
that there is apparently a single D.peltata form in W.A., N.Z., Japan,
and elsewhere, while there are numerous D.peltata forms in SE Aust. There
is actually someone at the moment in SE Aust. who believes that there are
a few species present in this peltata-complex (which you would probably
call subsp.) and is working on publishing them. Maybe D.auriculata is
truly a good species.
About that D.insolita, I imagine there are few colections of it,
but did any actually come with the tuber? And if the differences are so
few, why did you leave it as a separate species instead of putting it as
a subsp. of D.peltata?
All the Best,
Fernando Rivadavia
Tokyo, Japan