shrub on coarse gravelly volcanic soil of wide, braided sheet-wash arroyo draining coastal plain between rhyolite hills. Sometime confused with(or merged into) M. tomentosa but leaves are greenish, stellate-puberulent, and not greyish canescent and densely tomentose as in M. tomentosa, among other differences.
rare herbaceous plant adventive in landscape planter. Most if not all of the few records for this somewhat weedy, herbaceous tropical species, north of Navojoa and tropical deciduous thorn scrub in Sonora, seem associated with urban areas (only 2 found from the San Carlos area, 3 near Hermosillo), suggesting possible wild introduction via local garden use.