Sub-species
subsp. albescens
This sub-species is naturally found in Arizona.

subsp. elongata
This sub-species is naturally found in Arizona and New Mexico.

subsp. fendleri
This sub-species is naturally found in Arizona, New Mexico, Colorado, Kansas and Texas.

subsp. tripartita
This sub-species is naturally found in Arizona and New Mexico.

subsp. venusta
This sub-species is naturally found in Arizona.