Pineneedle Milkweed

on volcanic rhyolite tuff roadcut just below upper canyon rim. This once exciting swithback road has now been replaced with a new paved roadway to Batopilas that considerbly limits access to many former rich roadside collecting sites

roadcut in steep upper-canyon walls of volcanic rhyolitic tuff

roadcut in steep upper-canyon walls of volcanic rhyolitic tuff

roadcut in steep upper-canyon walls of volcanic rhyolitic tuff

roadcut in steep upper-canyon walls of volcanic rhyolitic tuff

roadcut in steep upper-canyon walls of volcanic rhyolitic tuff

Shrubby perennial plant on open sunny roadside on volcanic tufaceous rhyolite substrate.

open sunny roadside on volcanic tufaceous rhyolite substrate. Note buds forming inflorescence of compact axil cymes

on open sunny road cut in volcanic rhyolitic tuff

on open sunny road cut in volcanic rhyolitic tuff

on open sunny road cut in volcanic rhyolitic tuff