Clinacanthus siamensis  

Shrub,stem subterete, slight striate,glabrous. Petioles 1-2.5 cm. a long. Leaves blade lanceolate or elliptic or ovate, 4-13 cm x 1-5 cm.,  on both sides glabrous, base acute or subacute or oblique, apex acuminate, margin entire or crenate, secondary veins 5-6 on each side of midvein. Inflorescence cyme,  terminal. Rachis puberulent. Bracts and bracteoles linear, 6-7 mm. long, glandular-puberulous. Pedicels ca. 3-4 mm.long. Calyx lobes linear, 10-11 mm. long,  glandular-puberulous. Corolla 4-5 cm. long, outside glandular-pubescent, inside pubescent near the base. Lower lips 15 mm. long, apex obtuse,  upper lip deltoid 16 mm long, apex emarginated. Stamens exserted from mouth of corolla; filaments 1.2–1.3 cm, glabrous; anthers ovate-linear, 4 mm long. Disc annular, glabrous. Ovary and style base glabrous; stigma shortly bilobate. Capsule not yet seen.