Description: Herb, 10-20 cm, or up to 1 m tall, without spine; pubescent on stem, petioles, lower surface of leaves, outside calyx, inflorescence, bract and bracteoles. Leaves opposite, elliptic to lanceolate or ovate to ovate-lanceolate, 5–17 cm long; apex acute; base acute to obtuse or subcordate; margin inconspicuously serrate, apiculate; petiole 0.5–2 cm. Spike terminal, 3-8 cm or longer with 4-ranked flowers; bracts ovate to obovate, 0.5–1.5 cm long, apiculate; bracteoles 2, lanceolate to oblanceolate, ca as long as bract, margin ciliate. Flowers white, bilabiate. Calyx lobes oblong to lanceolate, 1-2 cm, ciliate. Corolla white, to ca 2 cm long, villous; lobes orbicular, ca 5 mm, apex emarginated. Stamens 2-paired, inserted at corolla mouth; filaments thickened, to ca 7 mm; anther 1-theca, linear, ca 5 mm, pilose. Ovary 2-locular; style to ca 1 cm, stigma 2-cleft. Capsule ellipsoid, to ca 1 cm long, 4-seeded, reniform, ca. 2 mm, glandular retinacula hook-like.

Thai name: หางจระเข้ (hang chora khe)

Photos: Preecha Karaket