USA, Arizona, Coconino County, Grand Canyon National Park, near boat launch below (south of) Phantom Ranch, between the two suspension bridges near archaeological site in delta along Colorado River, river right.
Locally common, plants 3-4 pads high, flowers 70(h)x80(w) mm, 73x65 mm, 60x73 mm, inner tepal 38x38 mm, broadly obovate, outer tepals light yellow with maroon flush midstripe and tips, inner tepals yellow with narrow, lighter maroon red flush midstripe, other two flowers lighter maroon on outer tepals, very little if any on inner tepals, filaments light chartreuse basally, becoming cream-white - very light chartreuse distally, anthers yellow, style white, stigma lobes dark green.
flowers
Suggestive of a hybrid between unusual O. cf. phaeacantha and O. engelmannii. Sheet II / II. Photos.