Don't sit on this! UV-reflective cactus spines.

[Andrea B.]

This is a hedgehog cactus, probably Echinocereus trioglochidiatus, the Kingcup or Claret Cup Cactus.I keyed it, but it is still in its winter mode so I won't be sure of the species until it blooms. I'm not very familiar (yet!) with keying and naming cacti.

 

There are 8 or 9 stems, or hedgehogs, in this one. In winter some of the cacti take on a reddish tone, quite evident in the visible photo. The spines are almost all very UV-bright. I don't know why a few are not. It probably has something to do with stage of growth or growth failure?

 

I find these Echinocereus growing under the big Juniper monosperma shrubs.There is probably some mutual benefit thing going on?

 

 

Visible

 

 

UV with UV-Baader

 

 

 

There is not a lot of false colour in this cactus, at least at this time. I did the color patch analysis on the bits of false colour I could see. It's the usual yellow/blue. The very dark yellow looks greenish to me. As usual, resizing and sRGB color mode have probably shifted colors a bit in the posted versions. I worked on TIFs to sample colour.

[Cadmium]

Nice pics, Andrea. Hmm, it almost has a purplish skin in visual.

D850 stock for the visual? D610-UV/IR for the UV?

[Andrea B.]

D610 for all.