ACANTHACEiE, 
245 
Order LXXV. ACANTHACEiE. 
Flowers irregular, hermaphrodite. Calyx inferior, persistent, usually 
4-5-partite, with unequal divisions. Corolla with a long tube and 5 
bilabiate or subequal imbricated or contorted lobes. Stamens 4, 
didynamous, or the anterior pair abortive ; filaments subulate, inserted 
low down in the corolla-tube ; anthers 2-celled, the lobes not always 
parallel, sometimes one aborted, dehiscing longitudinally. Ovary 
superior, 2-celled ; ovules 2 or more in a cell ; style filiform, usually 
entire. Fruit a capsule, with two loculicidal valves opening elastically 
from the top. Seeds exalbuminous, usually borne on distinct spine-like 
processes (retinacula). — Herbs or shrubs with exstipulate opposite 
simple leaves, the flowers often showy. Distrib. Hound the world 
in the tropics. Species 1300-1400. 
Climbers. Capsule without retinacula * Thunbergia, 
Erect. Seeds borne on retinacula. 
Corolla with 5 short obtuse nearly equal lobes. 
Perfect stamens two * Barleria. 
Perfect stamens four 1. Asystasia. 
Corolla distinctly bilabiate. 
Anthers 1 -celled 2. Hypoestes. 
Anthers 2-celled. 
Flowers in terminal spikes 3. Justicia. 
Flowers in axillary umbels 4. Dicliptera. 
* THUNBERGIA, Linn. 
Calyx globose, small, persistent, with 12-15 long linear teeth, 
which become rigid, at first hidden by two large ovate membranous 
bracts. Corolla with a long funnel-shaped tube and 5 nearly equal 
spreading obovate lobes. Stamens 4, didynamous, inserted near the 
base of the corolla-tube ; filaments short ; anthers 2-celled, oblong, 
adnate. Ovary ovoid, 2-celled; ovules 2 in a cell. Capsule globose, 
abruptly beaked, dehiscing by 2 recurved valves; retinacula none. — 
Twining herbs, with opposite cordate or hastate leaves, the flowers 
showy, axillary, pedicelled. Distrib. Tropics of the Old World. 
Species 30. 
Petiole terete * T. pragrans. 
Petiole distinctly winged * T. alata. 
* T. alata , Bojer in Hook. Flor. Exot. t. 177, a native of Tropical 
Asia and Madagascar, is naturalised in Mauritius by roadsides at 
Pamplemousses and in other parts of the island. It is a herbaceous 
climber, with densely pilose stems and leaves, distinctly winged 
petioles 1-2 in. long, a membranous cordate or hastate-ovate acute 
leaf-blade, slender terete pedicels exceeding the petioles, cordate- 
ovate acute pilose bracts \— f in. long, and a yellowish inodorous flower 
with an expanded limb 1-1| inch across. 
* T. fragrans, Roxb. PI. Corom. t. 67, widely spread in Tropical 
