- tiny annual with prostrate to ascending stems
- leaves opposite, narrowly oblanceolate, to ca. 3/4 inch long and 3/16 inch wide, with the toothless margins somewhat rolled under
- flowers solitary in leaf axils, about 1/8 - 1/4 inch long
- corolla white, 4-lobed
- fruit a 2-lobed capsule about 1/8 inch long (longer than its pedicel)
- many similar bluet species in South Texas
- key features of Croft's bluet: narrow leaves, axillary flowers, short straight pedicels
- grows in openings in brush on tight loamy soils
- endemic to South Texas, with records from 7 counties