Penstemon cardinalis
Worthington, R. (2007). Lincoln National Forest, Inventory Completion Report, Sensitive Plant Survey, Guadalupe Rabbitbrush Surveys. Guadalupe RD, Lincoln NF, USFS. 2 p.
Map of scarlet penstemon and Kerr's milkvetch in Lincoln National Forest. 2006.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Sesntive Plant Survey, Field Notes. Guadalupe Rabbirbrush 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. 6 p.
Worthington, R.D. (2007) Lincoln National Forest, Inventory Completion Report, Field Notes. Guadalupe Rabbitbrush Surveys 2007, Guadalupe RD, Lincoln NF, USFS. 3 p.