Nice color variation, with spring here but enough chill at night + dryness to keep some pads (stems) purple or rosy.
The Dave Ferguson, El Cactosero de Burque, just spoke up, "This is typical Opuntia macrocentra, just not a very spiny one...I doubt this plant has any connection to your Tubac plant". I guess he's right. We have a few Opuntia macrocentra growing near the garage, just 50 feet north and higher up. With all the birds and squirrels that eat the tunas (prickly pear fruit), that makes sense. Some of those are from cuttings I took off nearby wild plants, before development happened along Tramway.
There used to be several Opuntia santa-rita 'Tubac' on this baking hot, west-facing ledge below our house, inspired by the rock ledges W of Carlsbad, enroute to Queen NM or Carlsbad Caverns HQ. A freakish 18" snow, followed by a few recent cold winters, damaged them severely (so much for microclimates). But the ocotillos, verbenas, and nopales continue to thrive and grow. There wasn't enough room, anyway.
Long spines & a respectable amount of golden glochids say, "back off!"
Above - Cane or Spiny Cholla (tallest - R), green Texas Sotol (behind slope), powdery-blue Mescal Agave (L), green Lechuguilla (front and pupping all over), and some unpruned-as-of-yet Green Brittlebush.
Both areas might get a soaking of water by hand once a year.
Below - bare Ocotillo waiting to for flower buds and then leaf-out (L), green Engelmann Prickly Pear (L), Blue or Wheeler's Sotol (R), and Ma Huang (rear on ledge - R). Our property top-of-ledge; Open Space below wall:
And serious weeds mixed in with the verbenas on the ledge, and about 10' / 300 lbs of falling cacti one can't see from here, meaning my maintenance work is cut out for me. But monetary-type work, first.
Thanks, Agave Compadre de la Estrella Muerta (aka Pam) for the 3/2012 Foliage Follow-Up! Visit it ASAP - here.