Description from Flora of China
Herbs or shrubs, erect, robust. Stems to 1.5 m tall, apically tawny stellate lanate, basally scabrid or sparsely stellate lanate. Petiole 1-3 cm; leaf blade 19-21 × 3-9 cm, abaxially densely gray or tawny stellate tomentose, base cuneate or obtuse, margin coarsely serrate to inconspicuously serrulate, apex acuminate to obtuse. Cymes axillary, crowded, many flowered, subsessile; bracts and bracteoles linear-lanceolate to linear, 7-10 × 1-2 mm. Calyx campanulate, 9-10 × 5-6 mm, densely stellate tomentose, dilated and eventually splitting in fruit; teeth triangular, 2-3 mm, apically short needlelike. Corolla white to yellowish, ca. 3.5 cm, puberulent; tube ca. 2 mm wide at base, ca. 10 mm wide at throat; upper lip straight, circular, ca. 6.5 × 7.5 mm; lower lip ca. 10 mm, middle lobe circular, ca. 5 mm in diam., lateral lobes ca. 4.5 × 6.5 mm. Nutlets 4, compressed obovoid, 4.5-5.5 × 3.5-4 mm, white, tawny when dry, scabrid, covered with sparse, stellate hairs. Fl. Apr-Jul and Oct-Jan.
Densely forested valleys, grassy streamside slopes; 100-1400 m. Guangdong, Guangxi, Yunnan [India, Laos, Myanmar, Thailand, Vietnam]