Needleleaf Bluet

Houstonia acerosa A. Gray; Benth. & Hook. Gen. 2: 60. 1873
Hedyotis acerosa A. Gray, PI. Wright. 1: 81. 1852. Oldenlandia acerosa A. Gray, PI. Wright. 2: 67. 1853. Mallostoma acerosum Hemsl. Biol. Centr. Am. Bot. 2: 31. 1881. Ereicoctis acerosa Kuntze, Rev. Gen. 281. 1891.
Erect or ascending cespitose shrub, 0.5-3 dm. high, fruticose nearly throughout, the stems usually numerous, simple or sparsely branched above, angulate and striate, scaberulous or minutely hirtellous, the internodes usually much shorter than the leaves; stipules 1 mm. long or shorter, whitish, setuliferous or cuspidate; leaves mostly 3or 4-verticillate, sessile, 5-12 mm. long, rigid-setaceous or acerose-linear, scaberulous or hirtellous or glabrate, suberect; flowers axillary or terminal, sessile or rarely very short-pedicellate; hypanthium scaberulous, short; calyx-lobes setaceous, 3-6 mm. long, scaberulous or hirtellous, in fruit usually longer than the capsule; corolla 12-16 mm. long, the tube slender-funnelform, glabrous, the lobes ovate, 8
mm. long or shorter, acute, sometimes less than half as long as the tube and sometimes two
thirds as long, whitevillosulous within; capsule subglobose, 2.5 mm. long, about two thirds
inferior, shallowly bisulcate, rounded or slightly retuse at the apex, densely hirtellous; seeds
crateriform, 0.8 mm. long, black, minutely roughened on the back.
Type locality: High prairies, from Live Oak Creek to Las Moras, western Texas. Distribution: Western Texas to Coahuila and San Luis Potosi.

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.