SE Arizona perennial Tithymalloids

This is just so I can keep track of the different forms of the perennial Tithymalloids (subg. Esula) I saw on the SE AZ iNatathon earlier this year. One of the forms is quite odd and doesn't fit the descriptions of either E. brachycera or E. chamaesula very well.

Dichasial bracts elongated; mostly convergent horns: (Discussion) (Discussion)

Dichasial bracts less elongated; mostly divergent horns:

Posted on 20 October, 2017 22:13 by nathantaylor nathantaylor


Euphorbia iNaturalistensis! ;)

Posted by sambiology over 6 years ago

@sambiology I appreciate the attempt to make sense of these plants. The plants in all of these observations closely match the tightest concept of Euphorbia brachycera Engelm. There's been a lot of confusion due to the inclusion within E. brachycera of a lot of the Rocky Mtn stuff that is better treated, as you're obviously realizing, as a different species (Euphorbia robusta). The reason this is so confusing is that few think about looking at the type material of Euphorbia brachycera from central Texas or the variation in that area to get a sense of what the plant and its habitat might look like. In the area where the type was collected, the plant grows in mesic canyons where there's often Acer grandidentatum. Floristically these areas are related to the places in the Chiricahuas where you're seeing this plant. Ever been to Boot Springs in the Chisos? You'll see the same thing and maple. I'd be the first to admit there are many populations from New Mexico across Arizona that defy classification but these plants are not a problem to identify. The iNat forum has been a great learning tool for me as I don't get to see everything in the field. It is most helpful when things are identified in a way that is consistent with the variation.

Posted by spurgeckr about 3 years ago

@nathantaylor I just realized this is your post but nothing changes.

Posted by spurgeckr about 3 years ago

Hahaha -- I'm just a fan of Nathan. :)

Posted by sambiology about 3 years ago

Who wouldn't be! A great and an intellectually curious person. Go Nathan!

Posted by spurgeckr about 3 years ago

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