Collected
18 August 1990.
San Luis Potosí, Mexico
Locality: Road to Real de Catorce, 12 mi. S of main highway W of Matehuala.
Environment description: Rocky limestone slopes with numerous Aplopappus sp., Opuntia tunicata, Opuntia microdasys, Agave lechuguilla, Salvia pinnellii.
Number of plants sampled: 2