In article , "P van Rijckevorsel" wrote:

Phred schreef
One of the big differences I noticed between the thorn-veldt of S.
Africa and a similar low vegetation in SW Madagascar was the
relative absence of thorny species in the latter superficially similar
looking communtities. (With the notable exception of the strange
_Didieria madagascariensis_ !)

As a top of the head interpretation, I assumed it was the lack of the
typical African grazing herds in Madagascar that resulted in a much
more friendly vegetation for collectors in shorts. :-)

"P van Rijckevorsel" wrote:
That seems to be the consensus opinion.
However Didieraceae ('Madagascar cacti') contains some four genera with ca
ten species, not just the one species. These should all be pretty
weird-looking.

Phred schreef
I probably only really noticed the tall species fairly common around
Tulear -- well, I assumed it was all one species -- and it was
certainly pretty weird.

One of these days, if I ever get round to my threatened task of
scanning many of my Kodachromes, and if I ever also get round to
setting up a web page, I might be able to put up a few images of such
things when they get mentioned around here. But, please, no one hold
your breath.

+ + +
These days we don't have to wait for that. Plenty of images on the web. Of
this family Alluaudia is the biggest both in number of spp and in physical
stature (to 10m)

pictures of Alluaudia

http://www.dipbot.unict.it/orto/1054-1.html

http://c2.webshots.com/photo/2628826...0199ZhitTGjKNI

http://community8.webshots.com/photo...9384kVWobnUQan

http://c2.webshots.com/photo/2628826...8424rRqExGZxCQ

pictures of Didiera
http://www.botany.hawaii.edu/faculty...id_tro_hab.jpg

http://community9.webshots.com/photo...47194591SXsLjY

Thanks for the URLs. The Alluaudia shots are quite nice; the Didieria
leave a bit to be desired. My "Didieria" looks more like these
Alluaudia in general, but the leaves are different -- IIRC without
digging out my slides of 30 something years ago. 8-)


Cheers, Phred.

--
LID