Erect subshrub, up to 2.5 m high. Leaves chartaceous, oblanceolate, lanceolate, or elliptic, 15-29 by 5.5-14 cm; Inflorescences in the axiles of foliage leaves, simple or sparsely branched, up to 8.5 cm long, spici- or racemiform, internodes spacious, puberulous; Stamens in 2 whorls: Capsules (rather young) pendent, siliquiform, twisted, narrowed at both ends, puberulous. Seeds ellipsoid, c. 2.5 by 1.5 mm, tubercled, deeply furrowed.
Asahan present, Asia-Tropical, Atjeh present, Div. Padang present, Gunung Leuser Nature Reserve present, Northern Sumatra present, Tapanuli present, Upper Bila present
Malesia: Northern Sumatra (Atjeh: Gunung Leuser Nature Reserve; TapanuliDiv. Padang; East Coast: Asahan and Upper Bila).
The flowers remind of T. borneensis; differs from that species by loosely pubescent (not densely sericeous) leaf undersurface, venation at base reticulate (not transverse), rachis with spaced bracts and long internodes, perianth without a distinct annular fold or ridge inside the mouth of the tube, and reniform lobes.