Flora of the Hawaiian Islands
Dicotyledon Literature for Thunbergia fragrans
Smith, 1991; Wagner et al., 1990, 1999; Lorence & Wagner, 2020.
   Acanthaceae -- The Acanthus Family Bibliography
      Thunbergia fragrans

Common name(s): white thunbergia, sweet clock-vine
General Information
DistributionNative to India and Ceylon.In the Hawaiian Islands, naturalized on Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i. First collected 1916, Forbes 611.K (BISH).

HabitatCultivated in Hawai'i, now natrualized at least on Kaua'i, O'ahu, Maui, and Hawai'i, but probably on all of the main islands.
Herbaceous, scrambling or climbing vine with slender sinistrorsely twining stems.
Leaves petiolate; blade hastate-ovate, 3‒10 cm long, 1.5‒5 cm wide, broadly obtuse to truncate at base, margin subentire, often with pair of large teeth toward base; petiole unwinged, 0.5‒7 cm long.
Inflorescences a solitary flower, axillary, pedicellate, subtended by 2 lanceolate to ovate bracts 13‒15 mm long. Flowers with 15‒16 calyx lobes; corolla white, tube 2‒2.5 cm long, limb 4‒5.5 cm across.
Fruit 2.2‒2.5 cm long, body subglobose-didymous, 0.5‒0.7 cm long, 1 cm wide, beak flat, 1.5‒1.7 cm long.
Seeds 2‒4, lenticular, biconvex, 5‒6 mm long, 3 mm wide, brown, surface rugose.
Despite the specific epithet, flowers of this species are not noticeably fragrant at any time of day or night.
David Lorence