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Drosera ascendens - villosa - graomogolensis

Hi!

Can anyone please tell me how to distinguish between Drosea ascendens, graomogolensis and villosa ? By looking on Fernando Rivadavia's pictures ( http://www.mcef.ep.usp.br/carnivo....sa.html ) i suppose the following :

Drosera villosa is getting really big with upright leaves (similar to Drosera venusta). The petioles are longer, than in the other two.

Drosera graomogolensis ist stem-forming.

Drosera ascendens (or villosa ssp ascendens) doesn't form a stem and grows as a rosette.

Are there any differences in the flowers or seeds as well ?

Based on this, i would say, the plant i'm growing is not Drosera villosa, but Drosera ascendens. Here are two pictures :
ascendens_001_05_06102003_001tn.jpg

higher resolution

ascendens_002_05_06102003_006tn.jpg

higher resolution

Christian
 
Hi Christian,

Well, if you adopt Dr. Schlauer's revision of Drosera species as published in the 1995 CPN, then your plant must be legitimately referred to as simply D. villosa.  There is no legitimate variteal status assigned to any members of D. villosa.

For horticulturalists, we need to seggregate the different location forms: D. villosa is very variable across its range.  Some have longer petioles, some less so.  The plant in the photo appears to be the form found in the Serra Do Caparao according to personal communication with Fernando.  This is the most commonly cultivated form in circulation, but there are others as well from different locations.  All are simply D. villosa as far as legitimate publication are concerened.

D. graomogolensis seems rather less variable from what I have seen.  As to specific differences, there are many.  Most obvious is the overall general form, D. graomogolensis has a more upright character, superficially similar to D. venusta, whereas the D. villosa you have forms flatter rosettes of a greater circumference.  D. graomogolensis has shorter petioles as well.

There are differences in both flowers and seeds as well.  There are fine line drawings in the Silva and Giulietti's "LLevantamento Das Droseraceae do Brasil" Bol. Bot. Univ., Sao Paulo 16: 75-105 1997.  

In the photo below, D. graomogolensis is on the lower left, D. villosa "var. ascendens" is on the right.  Don't go by the color, both plants become equally as red.  The D. graomogolensis in the photo was recently acquired when this photo was taken.


Drosera_graomogolensis_with_D_villosa_var_ascendens_081203_1r.jpg


Some additional photos of these species in habitat may be found on my website at:

http://f1.pg.photos.yahoo.com/ph.....view=t

These come courtesy of Robert Gibson and Fernando Rivadavia: Robert provided the photos, and Fernando edited the photos for accuracy. If you are a yahoo member, you can view the full file size (sign up is free and worth it to be able to see them. Yahoo mail also offers free webspace, in case you are interested, and I am on Yahoo messenger service as well.).
 
Hello all, Zach here,
not to add to this confusion, but Christian, your plants look very similar to my D.montana tomentosa. My plants have grown quite green from a lack of light, but the leaves are around the same shape and petiole length is about the same size. Any ideas?
 
errr, scratch that lol,

I have looked more closely to my plants (montana,) and it is indeed different. Sorry for any confusion (darn, thought I had villosa for a sec
blues.gif
)

Christian, do you have any extra plant (s) for trade? I am trying to collect some South American dews now, but all I have are sessiflora and montana tomentosa. Thanks all-Zach
 
Yes, the lamina of D. montana var tomentosa are much more round, and the petioles much shorter than in D. villosa, but similar to D. graomogolensis except not held erect.

Zach, my plants should flower next season and I will be glad to send some seed of this species when I get it. I know how hard it is to find these plants.



Drosera_montana_var_tomentosa_BCP_033103_1_001.thumb.jpg
 
nice plant Tamlin,
I do indeed see the differences in size of the petioles. My tomesntosa's are putting up some scapes, so I'll have seed soon as well. Thanks-Zach
 
Zach,

It must be a seasonal thing for D. montana var tomentosa as mine are flowering too. Do you know the location origin of your plants? Maybe we could swap seed. My plants which are putting up scapes are from Diamantina, and were collected there last fall by Robert and Fernando. I am surprised they are flowering at such a small size, and a little more than a year after sowing the seed!
 
Hi Tamlin,
Sorry, but my tomentosa don't have any locational information with them. All I can say is that they were purchased at a bacps meeting and that they are quite hairy. Thanks-Zach
 
Hey Guys,

It's true you can't formally use D.villosa var/subsp. ascendes, but the name D.ascendens is legitimate. This is how Saint Hilaire originally published them, as 2 separate species (D.villosa and D.ascendens). They are simialr in floral parts, but the leaves are different in that D.villosa has petioles longer than the lamina while D.ascendens has petioles usually much shorter than the lamina, but in shadier habitats they may be almost equally as long. D.villosa usually has narrower, more upright leaves too. D.ascendens is extremely variable in the wild. The larger plant on the right in taht 1st picture seems like the form from the Serra dor Orgaos (or Orgelgeberge, or something like that in German), which is the one most common in cultivation (and not the one from Caparao, William).

As for D.graomogolensis, the rosettes are almost identical to some forms of D.ascendens. Here the differences are in the floral parts and seeds. The seeds of D.graomogolensis are rounder, the flowers fewer, pedicels longer, sepals smaller, petals parger, stamens larger, styles longer, and scapes longer too I think.

And there's a 4rth taxon to this complex, but I think it was lost in cultivation...
 
  • #10
Thanks Fernando. The plant was very small when I sent it you that photo, and I have updated my list. It's great to have you here to comment, as my experience is very limited with the Brasillian taxa.

Would you also confirm that the smaller plant is D. graomogolensis?
 
  • #11
Hi,

Thanks all for your answers! You've been a great help to me. So i think, the plant i'm growing is a Drosera ascendens or graomogolensis. I can't wait to see see a flower of my plant.

Christian

P.S.: I think, it's Orgelgebirge, Fernando
smile.gif
 
  • #12
Sorry William, but it's very hard to tell even between mature rosettes of ascendens and graomogolensis, you'll have to wait for flowers. It is so confusing that Robert Gibson and I THOUGHT we'd found a new population of graomogolensis on our trip together, but I'm almost sure they're ascendens, only slightly large and hairy.
 
  • #13
Fernando,

Well, we won't have long to wait: one of my "tentative"  D. graomogolensis plants is initiating a flower scape right now, I just noticed it today!  But I will bet my cat against a packet of rare Brasillian seed (your choice!) that it is truly D. graomogolensis!  The stipules are in conformity with this species, and are really distinct from the D. ascendens that I cultivate: much more imbricate, and the longer stalked glands on the adaxial lamina surface are apparent.  Aww, heck, you won't take the bet now.  Should have kept quiet on that stuff.

So, can I rely on the characteristics of the respective stipular indumentum, or is this a plastic quality? D. ascendens is nearly covered with nearly sessile glands vs D. graomogolensis which has longer stalked glands of lesser occurence? Or am I being optimistic with this?
 
  • #14
Hi,

I took some pictures of this plant today. that i would like to share with you. I didn't want to open a new thread.


ascendens_003_05_2201004_002tn.jpg
[/
http://www.utricularia.net/drosera/ascendens_003_05_2201004_002.jpg

ascendens_005_05_2201004_016tn.jpg

http://www.utricularia.net/drosera/ascendens_005_05_2201004_016.jpg

ascendens_006_05_22012004_026tn.jpg

http://www.utricularia.net/drosera/ascendens_006_05_22012004_026.jpg

ascendens_004_05_2201004_011tn.jpg

http://www.utricularia.net/drosera/ascendens_004_05_2201004_011.jpg

the links under the pictures will lead to the same picture in a higher resolution. I don't know, why i can't link the pictures directly anymore.

Christian
 
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