Penstemon cardinalis ssp. Regalis
Baker, M. (1999) Multiple Bundled Lincoln National Forest Inventory Completion Reports, Sensitive Plant Surveys, Field Notes. Lincoln Supervisor's Office, Lincoln National Forest, USFS. 54 p.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Field Notes. Guadalupe Rabbitbrush Surveys 2007. Guadalupe RD, Lincoln NF, USFS 3 p.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Field Notes. Guadalupe Rabbitbrush Surveys 2007. Guadalupe RD, Lincoln NF, USFS. 3 p.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Field Notes. Guadalupe Rabbitbrush Surveys: 2007. Guadalupe RD, Lincoln NF, USFS. 3 p.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Sensitive Plant Survey, Field Notes. Guadalupe Rabbitbrush Surveys: 2007. Guadalupe RD, Lincoln NF, USFS. 3 p.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Field Notes. Guadalupe Rabbitbrush Surveys: 2007. Guadalupe RD, Lincoln NF, USFS. 3 p.
Worthington, R.D. (2007) Lincoln National Forest Inventory Completion Report, Sensitive Plant Survey, Field Notes. Guadalupe Rabbitbrush Surveys, Guadalupe RD, Lincoln NF, USFS. 3 p.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Field Notes. Guadalupe Rabbitbrush Surveys 2007, Guadalupe RD, Lincoln NF, USFS. 3 p.
Worthington, R.D. (2007) Lincoln National Forest, Sensitive Site Reports, Population Site Report, Field Notes. Population # PECAR-11, Guadalupe RD, Lincoln NF, USFS 3 p.
Worthington, R.D. (2007) Lincoln National Forest, Sensitive Plant Site Report, Population Site Report, Field Notes. Population # PECAR-5, Guadalupe RD, Lincoln NF, USFS. 3 p.