Houstonia acerosa

Houstonia acerosa, the New Mexico bluet or needleleaf bluet, is a plant species native to Chihuahua, Coahuila, Nuevo León, Tamaulipas, San Luis Potosí, Texas and New Mexico.
Houstonia acerosa is an herb up to 20 cm tall, with narrow needle-like leaves and white or purplish flowers.

Varieties

Three varieties of the species are widely accepted:

Houstonia acerosa var. acerosa - Coahuila, Nuevo León, Tamaulipas, San Luis Potosí, Texas
Houstonia acerosa var. polypremoides Terrell - Chihuahua, Coahuila, New Mexico, trans-Pecos Texas
Houstonia acerosa var. tamaulipana Terrell - Tamaulipas