Herbs, perennial, cespitose, dark brown to reddish brown or brownish olive when dry, to 4.5 dm, not glaucous. Stems simple, 0.9-2.1 mm wide, glabrous, margins usually entire, usually not hyaline, similar in color and texture to stem body. Leaf blades glabrous, bases becoming fibrous, persisting in tufts. Inflorescences borne singly; spathes often purplish brown, glabrous, keels entire; outer 15-33 mm, 6.2-13 mm longer than inner, basally connate 1-2.7 mm, tapering evenly towards apex; inner with keel gibbous basally, hyaline margins 0.5-0.6 mm wide, apex rounded or truncate, somewhat erose, usually extending beyond green apex as 2 lobes. Flowers: tepals blue to bluish violet, bases yellow; outer tepals 7.8-13 mm, apex rounded to slightly emarginate, aristate; filaments connate ± entirely, slightly stipitate-glandular basally; ovary similar in color to foliage. Capsules dark reddish brown, ± globose, 2.7-4.3 mm; pedicel spreading to ascending. Seeds globose to obconic, lacking obvious depression, 0.5-1.1 mm, rugulose. 2n = 32.
Flowering spring, sometimes again in fall. Low, moist areas, sandy grasslands or pine woods, roadsides; 0--30 m; Ala., La., Tex.
K. L. Hornberger (1987, 1991) and D. S. Correll and M. C. Johnston (1970) considered Sisyrinchium texanum to be conspecific with S. sagittiferum (Correll and Johnston called it a 'hybrid form'). E. P. Bicknell, however, described S. sagittiferum as being unbranched, and the single (poor) type specimen (Riddell s.n., NY) agrees. We follow Bicknell´s original concept of a single-stemmed S. sagittiferum. Sisyrinchium texanum, being branched, is not considered a synonym here.