> I'd like to think that these fast-moving, rectangular-tipped outer
> tentacles in Thelocalyx and Coelophylla are something which would be
> conserved as an advantage for future lineages
I don't think so. _Drosera_ has *adhesive* traps. So the movement does
not need to be fast (and fast movement is probably more energy
consuming - i.e. disadvantageous - than slower movement; I fear noone
has tested that yet, however). Anyway, there is no selective pressure
to retain fast movement in _Drosera_.
> , but it would be very hard
> to explain this characteristics being present in "primitive groups",
> unless they represent a lineage of their own.
Right.
> If we do accept this
> possibility though, we would have to believe that reduction from 5 to 3
> styles happened at least twice in Drosera: once from Thelocalyx to
> Coelophylla and once from an ancestor of Thelocalyx (which supposedly
> didn't have the fast-moving tentacles) to the rest of the Drosera.
Unlikely (reversal).
> I guess at least one proof that large, fast-moving tentacles are
> not essentially an advantage is clearly shown in Erythrorhiza, a
> supposedly "advanced group" where the tentacles are tiny, with practically
> no movement of the lamina itself, and even rare presence of glandless
> leaves. Who knows, the fast-moving tentacles in Thelocalyx and Coelophylla
> could be reminiscent of characteristics which eventually led to Dionaea
> and Aldrovanda.
Yes, indeed. Remember that the two latter genera have "primitive"
pollen types in Takahashi & Sohma's tree.
> >Chorological reasoning indicates such, however. The W half of S AM
> >(especially Colombia and Ecuador) is excepted; rather unusual for a
> >recently formed area (which should be more continuous).
>
> Explain better please, I didn't understand this part.
_D.anglica_ (recent spread) does not have large gaps in its total
range (except where expected: oceans, dry regions, &c.).
Thelocalyx has one besides the Pacific Ocean: the whole W of tr. S
AM. And this region is not devoid of _Drosera_.
> Just like we prefer to assume that no reversals occured, I'd say
> it's better to play safe and say that if two "ancient" species were
> separated for such a long time, they would be bound to be very different
> in the end, due to unevitable accumulations of mutations. And considering
> how uniform these 2 species are in their respective ranges (well,
> D.burmanni not as much maybe), I would suggest a recent spread, such as
> that which occured with D.anglica.
The difference does not need to be larger than between the two
species of _Mitrastema_ (Rafflesiaceae, E AS and Mexico) or the three
spp. of _Langsdorffia_ (Balanophoraceae, one each in Madag., N.Guin.,
and Mexico to S Brazil). These disjunctions are also generally
believed to be old.
> >Really? Exciting! I hope this "someone" will consider the problem on
> >a world wide scale, not limited to SE AU.
>
> Sorry Jan, but that's your job!! 8-)
Then the "someone" should stop before he starts seriously. I do have
enough to do already.
> >Barry Conn has discussed that in great detail, and I think he is
> >right.
>
> Sorry again, but who's Barry Conn?
You should know him, as he is a scientist who takes the time/does
the work others obviously don't before he starts publishing. He is
(the) one author from AU (Adelaide, I think) I know of who has
published some well researched papers on _Drosera_ recently. They are
certainly worth reading.
> >If you mean the key by "your recent list in CPN", _N.subtilis_ *is*
> >there on p.84 (under 1001011.).
>
> Wait a second, I'm confused here! I thought this plant was
> native to N.Australia
Right.
> and that it was a Lasiocephala!
Never.
> Don't ask me where I got this from,
OK, I won't ask but it would be interesting, though.
> I wouldn't remember myself, but are any of these 2 true,
Yes, 1 (v.s.).
> or were they in the past?
dto.
> >D.* tokaiensis obviously does not have an
> >independent existence outside the ranges of both parents. It should
> >be considered a hybrid (or hybridogenic species of recent origin)
> >like D.* obovata, and rather different from _D.anglica_ (which is
> >at least independent from the "other" parent, i.e. non-
> >rotundifolia). >
> It doesn't have an independent existence outside the parent's
> ranges, but it certainly DOES HAVE an independent existence.
No, just as much or as little as D.* obovata.
> Whether it is or isn't of recent origin, shouldn't disclassify a
> plant as a good taxon, it being hybridongenic or not.
I think it should if the situation is as clear as here. Scientific
hybrid names are made for naming hybrids, and not just for garden
lables.
Kind regards
Jan