Plant: annual; straight often stout hairs; stems 4-angled, decumbent, often much branched from the base, frequently rooting at nodes, 7-36 cm long Leaves: including leaf-like stipules appear whorled, 5-6 per node, 4-13 mm long, lanceolate-oblanceolate; apices acute or pungent; margins with white callous, with apically directed short stoutish hairs INFLORESCENCE: heads, solitary in upper axils on slender 3-25 mm long peduncles, the involucre commonly of 8 leaf-like lobes united 1/8-1/4 their length Flowers: 2-3 per head, sub-sessile, ca. 4 mm long, scarcely exserted from deeply divided involucre; calyx of 6 persistent teeth which crown the fruit; corolla pink or lavender, salverform, the tube slender, the limb usually 4-lobed, the lobes ovate, spreading; stamens included; pistil slightly exserted; mature carpels softly pubescent with appressed hairs; style filiform, 2-cleft Fruit: dry, didymous, separating into 2 indehiscent 1-seeded carpels Misc: Naturalized in lawns; 300-750 m (1000-2500 ft); Apr-May REFERENCES: Terrell, Edward E. 1995 Rubiaceae. Houstonia. J. Ariz. – Nev. Acad. Sci. 29(l): 36.