Endemic to northwestern Mexico where it is threatened by logging, land clearance for agricultural purposes and livestock grazing
Only known from a limited area in Mexico's State of Durango in western Zacatecas. It is uncommon and a decline is inferred from deforestation.
Habitat and Ecology
This variety occurs in oak-pine and pine-juniper woodlands and in adjacent grasslands.
This variety is used for fence posts and firewood.
Based on herbarium collections, this variety occurs in two or three locations (dependent on how one defines a location); perhaps there are 1–2 others as a sketch map in Adams (2011) suggests. Its AOO is certainly less than 100 km² however calculated, and is here estimated to be a mere 12km² based on reported rarity. The population is almost certainly declining due to exploitation and land clearing for agriculture. It meets criterion B for Endangered.
Unsustainable logging and land clearing for agriculture form the main threats to this variety. This variety seems rare and is located in a ranching/ grazing region.
No conservation measures are known to apply to this taxon.