Lagerstroemia poilanei 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 : 177-178

Lagerstroemia poilanei W.J.de Wilde & Duyfjes , sp. nov. — Fig. 1a

This species is distinct from the two most similar species, Lagerstroemia petiolaris and L. ruffordii , both of which have long petioles (10 mm or more), differing in smaller calyx tube with 6 sharp but not winged ridges continuing into the short pseudopedicel 1– 2 mm long (fruiting pseudopedicel 2–3 mm long). — Type: Poilane 6839 (holo P P05114587 ;iso P 2 sheets P05114583 , P05114586 ), Vietnam, Nhatrang , Nui Han Heo Peninsula, 12-06-1923, fr .

Etymology. The specific epithet honours Eugène Poilane, 1888–1964, French botanist and coffee planter in Indochina , who made one of the most valuable and largest botanical collections in that area.

Two varieties are recognised.

var. poilanei

Shrub or treelet 2.5–6 m tall, bark peeling (?). Leaves: petiole glabrous, 9–12 mm long; lamina thin, glabrous, elliptic, small, 3–6 cm long, base short-cuneate, apex subacute or bluntish; intercostal venation reticulate. Inflorescences terminal, paniculate, 3–6-flowered. Flowers: buds ± obconical to obovoid, (sub)glabrous; calyx tube c. 5 mm long, c. 5 mm diam at apex, 6-ridged, ridges sharp, not winged, running onto the pseudopedicel; pseudopedicel 1–2 mm long; auricles absent; calyx lobes 6, reflexed at anthesis, long-triangular, c. 3 by 2 mm, (densely) fine hairy at apex within; petals pinkish, c. 15 mm long including c. 3 mm long claw, margin short crispate-dentate; stamens numerous, radial symmetric, presumably dimorphic (outer stamens longer than numerous inner ones); ovary hairy. Capsules dark brown or black, smooth, not shagreen, glabrous or minutely hairy at apex, 5-valved, c. 10 mm long, c. 9 mm diam, apex rounded, calyx 6-ridged, ridges low, running onto the c. 2 mm long fruiting pseudopedicel; calyx lobes glabrous within, finally reflexed.

Distribution — Southern Vietnam: Nhatrang, Phanrang.

Habitat & Ecology — On poor sandy or rocky soil.

Specimens studied. VIETNAM, Khanh Hoa Prov., Poilane 2858, Isl. Tre near Nhatrang , 30 Mar. 1922, fr.; Poilane 3111, Isl. Tre near Nhatrang ( Moî village ), 22 Apr.1922, fr. ( P05115298 ); Poilane 4654, between Nhatrang and Ninh Hoa, 7 km N of Nhatrang , 21 Sept. 1922, fl.; Poilane 4848, Nui Han Heo near Nhatrang , 3 Oct. 1922, fl.; Poilane 6148, Hone Cohé near Ninh Hoa , Nhatrang , 30 Apr. 1923, fr.; Poilane 6836 B, Annam , Peninsula Nui Han Heo , 13 June 1923, fl. ( P05114584 ); Poilane 6839, Annam, Peninsula Nui Han Heo, 12 June 1936, fr., type; Poilane 9751, Ba Ran, 27 Feb. 1924, fr.; Poilane 9753, Ba Ran, 27 Feb. 1924, fl.; Schmid s.n., Ba Ngoi, 22 Nov. 1961. fr . – Ninh Thuân Prov., Poilane 5586, Annam , Ca-Na, 5 Mar. 1923, fl .

Note — With capsule is meant the visible part of the fruit above the calyx tube, the latter hiding the base of the capsule. The pseudopedicel is the narrowed pedicelliform basal part below the calyx tube and belongs to the flower; at base it ar- ticulates with the true pedicel.

var. grandis W.J.de Wilde & Duyfjes , var. nov.

Differs from the type-variety var. poilanei in larger fruit (visible part of capsule) 14–15 mm long vs fruit 8–10 mm. — Type: Poilane 8541 (holo P P04711372 ), Annam, Prov. Phanrang, 12 Feb. 1923, fr .

Etymology. The variety epithet grandis (Latin, grandis = big) refers to the larger fruits.

Tree 6–12 m tall, bark not recorded. Leaves: petiole glabrous, 10–12 mm long; lamina thin, glabrous, (ovate-)elliptic, c. 8 cm long, base (broadly) rounded or short cuneate, apex bluntish; intercostal venation reticulate. Inflorescences (infructescences) terminal, paniculate, 5–10-flowered. Flowers or flower buds unknown. Capsules black, smooth, not shagreen, glabrous (sparse weak minute hairs less than 0.1 mm long excepted), 5-valved, 14–15 mm long, c. 10 mm diam, apex rounded with short beak, calyx 6-ridged, glabrous, ridges low, hardly 1 mm high, shortly running onto the 2–3 mm long pseudopedicel; calyx lobes glabrous within, somewhat reflexed.

Distribution — Southern Vietnam ( Annam): Nhatrang, Phanrang.

Habitat & Ecology — Rocky soil; fruiting in February and September.

Specimen studied. VIETNAM, Khang Hoa Prov., Nhatrang, near Banghoï,

Fleury in Chevalier 39029 ( P P05114593 ), 27–29 Sept. 1918, fr .

Rotala

The two new Rotala species concern one species endemic in Laos with yellow flowers, a unique character in the genus, and one species discovered among the material of the widespread Rotala cordata . In the very variable and widespread R. indica some deviating specimens are here described as a new variety of R. indica .

Figures

Fig. 1 Fruits of the four Lagerstroemia species most similar in their comparatively long petioles, small few-flowered inflorescences, glabrous flower buds, and hairy ovaries. Note differences in size and expression of calyx ridges. a. Lagerstroemia poilanei W.J.de Wilde & Duyfjes var. poilanei, type; b. L. ruffordii T.T.Pham & Tagane; c. L. petiolaris Pierre ex Laness.; d. L. poilanei W.J.de Wilde & Duyfjes var. grandis W.J.de Wilde & Duyfjes (a: Poilane 6839, P; b: Tagane et al. 6971, L; c: Pierre 928, P; d: Poilane 8541, P). — Drawn by Jan van Os.