lophophora

Harvesting peyote is part of the Huichols' millennia-old traditions and an integral part of their religion and doesn't affect the peyote populations in nearly the same way as urban, industrial and agricultural development (if their harvesting had any major effect, their thousand year old history of doing so would have depleted the populations long ago). Maybe I'm just becoming a grumpy old man, but I find it good manners (and conducive to discussions) to quote your sources. The source (ad verbatim) of Teotzlcoatl's post can be found here (which happen to be my blog).

You might find Del Weniger's description of Lophophora williamsii var. echinata published in 1970 in Cacti of the Southwest (pp 95) interesting. Weniger distinguished the regular south Texas and echinata (Trans-Pecos) varieties primarily by cold hardiness, and stem size and number.

Teotzlcoatl, I'm not sure I understand your argument. You say "Obregonia, Leuchtenbergia and Acharagma are the cacti which are most closely related to Lophophora" and then you make a reference to what has to be the article Molecular systematics of Tribe Cacteae by Butterworth et al. It's correct that Butterworth's results demonstrate a very close relationship between Acharagma, Obregonia, and Lophophora but Leuchtenbergia is placed in an entirely different and not that closely related clade, the Ferocactus clade (check the diagram on p. 263 in the article). I don't see how you can use Butterworth for arguing a close relationship between Leuchtenbergia and Lophophora?

Thought I would share another time-lapse video of a flaccid Lophophora diffusa swelling with water. I'm a bit disappointed with how much (or rather how little) the plant actually swells - I guess I'll have to have another go at it next year

I've made a few time-lapse videos including one of a flowering Lophophora jourdaniana, a flowering Epithelantha micromeris v. greggii, and most recently one of a Lophophora diffusa unfolding its flower. I know it's not exactly recording the cacti's growth, but it's still fascinating to watch ;-) That being said, I'm currently in the process of shooting pictures of a L. diffusa swelling with its first drink of water in more than 4 months. If things go as planned the video should be ready in a few days. You also might want to visit Hydrocactus - the cactus video page; this site originally inspired me to start experimenting with cactus time-lapse videos.

You might be interested in checking out Del Weniger's "Cacti of the Southwest" or "Cacti of the Trans-Pecos & Adjacent Areas" by Powell et al. Unfortunately I'm traveling and can't give you the exact details, but as far as I remember Weniger distinguishes the two varieties primarily by cold hardiness, and stem size and number. The echinata variety having larger, solitary stems and being much more cold tolerant (as already mentioned above by trucha). The "preliminary results by Martin Terry" I'm referring to at my blog, are from the "Population Genetics of Lophophora williamsii" chapter of his PhD dissertation, A tale of two cacti: studies in Astrophytum asterias and Lophophora williamsii. The results are summarized in the discussion (pp 144-147) that, among other things, says "The fact that the Val Verde County plants show the same uniform genotypes as the Presidio County plants, and that both West Texas populations are genotypically and allelically distinct from the Starr County plants, suggests a West Texas vs. South Texas genetic demarcation".

Thanks. It's good to know that my ramblings (or at least some of them ;-) are appreciated.

Oops, didn't notice that Teotzlcoatl had already mentioned that...

For what it's worth, I just did a blog post on the Lophophora alberto-vojtechii description including a few pictures from the article: Lophophora alberto-vojtechii, a new miniature species in the genus Lophophora. But as kadakuda says you have to get hold of a copy of the Cactus & Co magazine ;-)