Oldenlandia microtheca (Cham. & Schltdl.) DC.

Oldenlandia microtheca (Schlecht. & Cham.) DC. Prodr. 4:
428. 1830.
Gerontogea microtheca Schlecht. & Cham. Linnaea 5: 169. 1830. Gerontogea Deppeana Schlecht. & Cham. Linnaea 5: 169. 1830. Oldenlandia Deppeana DC. Prodr. 4: 428. 1830. Hedyotis Deppeana Steud. Xom. Bot. ed. 2. 1: 727. 1840. Hedyolis microtheca Steud. Nom. Bot. ed. 2. 1: 728. 1840. Oldenlandia latifolia Mart. & Gal. Bull. Acad. Brux. II 1 : 235. 1844. Hedyotis latifolia Walp. Rep. 6: 55. 1846.
Perennial, erect or decumbent, sometimes geniculate and rooting at the nodes, 1-4 dm.
high, copiously branched, the branches slender, glabrous, or puberulent at the nodes, the
internodes mostly longer than the leaves; stipules 1-2 mm. long, the margins fimbriate, the
lobes mostly gland-tipped; petioles slender, 2-5 mm. long, glabrous; leaf-blades mostly ovate or
lanceolate, sometimes elliptic or broadly ovate, 1-4.5 cm. long, 2.5-18 mm. wide, acute to
attenuate at the apex, acute or acuminate at the base, usually rather abruptly so, thin, glabrous
or scaberulous on the upper surface, beneath slightly paler, glabrous or scaberulous, the costa
slender, prominent beneath, the lateral veins evident but very slender; flowers in terminal and
axillary cymes, the cymes slender-pedunculate, few-flowered, lax, the pedicels 3-12 mm. long,
filiform, glabrous, usually erect or ascending; hypanthium less than 1 mm. long, glabrous, the
calyx-lobes as long or longer, triangular-lanceolate, attenuate, distant in fruit; corolla 5-6
mm. long, white, the tube greenish, obconic, much longer than the calyx-lobes, the lobes much
shorter than the tube, papillose inside; style exserted; capsule hemispheric, 2 mm. long and
slightly broader, glabrous, bisulcate, smooth; seeds minute, angulate, brownish-black.
Type localityPapantla, Veracruz.
Distribution San Luis Potosi to Puebla and Yucatan.