Rotala indica (Willd.) Koehne var. minima W.J.de Wilde & Duyfjes, 2019

Wilde, W. J. J. O. de & Duyfjes, B. E. E., 2019, Three new species of Lythraceae and one new species of Stemonaceae described from Indochina, Blumea 64 (2), pp. 177-182 : 180

Rotala indica (Willd.) Koehne var. minima W.J.de Wilde & Duyfjes , var. nov.

This variety differs from the variable and widespread type variety in its tiny habit, erect or decumbent branches that do not root at the nodes and base, and its flowers in terminal spikes with bracts supporting single flowers about as long as the bract. In R. indica var. indica the (decumbent) basal portions of the branches root at the nodes and the bracts in the flower spikes are much longer than the flowers. — Type: Robinson 1530 (holo P P05134476), Vietnam, Annam, Nha-Trang and vicinity, 11–26 Mar. 1911.

Etymology. The variety epithet minima (Latin, minimus = small, very little) refers to the tiny habit of the plant.

Plants herbaceous, to 10 cm tall, erect or with few spreading or decumbent branches, not rooting at the nodes. Leaves 4 – 6 mm long, with cartilaginous margin. Inflorescences terminal, spike-like, the flowers solitary in the axils of bracts, as long as the bracts; bracts broadly elliptic, more or less imbricate, c. 3 mm long, about as long as the flowers, at apex broadly rounded or short-acute. Flowers as in the type variety. Capsules opening by 2 valves.

Distribution — Vietnam ( Annam): Khang Hoa Prov., Nhatrang and vicinity.

Habitat & Ecology — Flowering and fruiting in March.

Specimens studied. VIETNAM, Khang Hoa Prov., Nhatrang and vicinity, Pham Hoang Ho 5082, 1960, fl., fr.; Robinson 1512, Robinson 1235, Robinson 1530, type, all 11–26 Mar. 1911, fl., fr.

Note — The flowers are recorded as white ( Robinson 1235).