Thunbergia fragrans Roxb.

• Title

  Thunbergia fragrans Roxb.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Thunbergia fragrans Roxb.

• Description

  Flora Borinqueña Thunbergia fragrans Thunbergia blanca White Thunbergia Family Acanthaceae Acanthus Family Thunbergia fragrans Roxburgh, Plants of the Coast of Coromandel 1: 47. 1795. Thunbergia volubilis Persoon, Synopsis Plantarum 2: 179. 1806. Commonly planted in tropical gardens for its attractive white flowers, this slender, herbaceous vine often establishes itself in thickets, in waste grounds and on roadsides, and is occasional in Porto Rico as a naturalized plant in thickets and along roads; it is a native of the Old World tropics, but quite widely naturalized in the West Indies. Thunbergia commemorates Karl P. Thunberg, an eminent Swedish traveller and botanist, who lived from 1745 to 1828; the genus was dedicated to him by the botanist Retz in 1776. Some 40 species are known, all natives of the Old World; another of them, the Winged Thunbergia, or Redadera, is more abundantly naturalized in Porto Rico than the one here illustrated, and a few others are occasionally grown in gardens as large-flowered ornamental vines. Their leaves are opposite, mostly halberd-shaped or heart-shaped at the base, the flowers solitary or clustered, each subtended by a pair of leaf-like bracts; the corolla has an oblique tube, in some species enlarged upward, and a spreading, 5-lobed limb with broad lobes; there are 4 stamens in pairs of 2; the ovary is 2-celled, with only 2 ovules in each cavity and the style is dilated. The globular, leathery fruit is abruptly beaked and splits when ripe, releasing the seeds, which are borne on short projections termed retinacula. Thunbergia fragrans (fragrant) climbs to a length of 2 meters, or less, and is finely hairy. Its leaves are rather broad, long-pointed, often coarsely few-toothed, slender-stalked, and from 5 to 10 centimeters long. The flower-stalks are as long as the leaf-stalks, or longer; the bracts are lance-shaped, hairy, pointed, and from 1.5 to 2 centimeters long, much longer than the deeply cleft calyx; the bright white corolla is from 2.5 to 3 centimeters long, its lobes 3-toothed and nearly as long as the tube; the first is hairy, about 8 millimeters in diameter, and tipped by a stout, awl-shaped beak from 1 to 1.5 centimeters long. The flowers of this vine, as grown in Porto Rico, are delicately odorous, not strongly fragrant.