Lagerstroemia densiflora, W. J. de Wilde & Duyfjes, 2016

De Wilde, Willem J. J. O. & Duyfjes, Brigitta E. E., 2016, Survey of Lagerstroemia L. (Lythraceae) in Indochina (excl. Thailand) with the description of Lagerstroemia densiflora, sp. nov., a new species from Vietnam, Adansonia 38 (2), pp. 241-255 : 245

4. Lagerstroemia densiflora

W.J.de Wilde & Duyfjes, sp. nov. ( Fig. 4 )

Differs from similar Lagerstroemia duperreana Pierre ex Gagnep. in smooth, not ridged, calyx tube, shorter pseudopedicel in fruit (4-5 mm long), and in densely set flowers in multi- flowered inflorescences.

TYPE. — Vietnam, Annam, Prov. du Binh Thuan, Gia lê, 24. V.1905, Magnein 27 (holo-, P [ P05179657 !]) .

DISTRIBUTION. — Vietnam, Annam, Province du Binh Thuan, Gia lê; only known from the type .

HABITAT AND ECOLOGY. — Forest, on sandy loamy soil; flowering and fruiting in May.

ETYMOLOGY. — The epithet refers to the dense, many-flowered inflorescence.

NOTE. — The condition of the stamens, monomorphic or dimorphic, cannot be ascertained in dried flowers.

DESCRIPTION

Small tree; bark not recorded. Twigs terete, glabrous, finely longitudinally cracked. Leaves glabrous (glabrescent from minute grey stellate hairs). Petiole 0.5-0.6 cm long. Lamina narrowly elliptic, somewhat broadest below the middle, 11-12 by 3-3.5 cm, base short-cuneate, apex obtuse; lateral veins 10- 12 per side; intercostal venation finely scalariform- reticulate. Inflorescences terminal,compact,densely many-flowered,densely finely yellow-brown hairy, hairs sub-stellate, woolly,overall shape of inflorescence narrowly paniculate, apex broadly rounded, c. 13 cm long, 4-8 cm wide, composed of 6 or 7 pairs of main branches. Flowers: bracteoles minute, caducous or absent; bud obovoid, 5-6 mm long, apex rounded, without nipple; pseudopedicel at anthesis 3-4 mm long; calyx tube c. 5 mm long, smooth (not ridged), auricles absent but minute wart inside at sinus present; calyx lobes 6, reflexed after anthesis, triangular, c. 3 mm long, densely hairy in the upper part within; petals pink-purplish, caducous, obovate, c. 8 mm long including c. 2 mm long claw (estimated), margin entire; stamens numerous, presumably monomorphic (but see Note), 5-6 mm long, anthers c. 0.5 mm diam.; ovary subglabrous (i.e. sparsely set with minute whitish ephemeral caducous hairs), subglobose. Capsule glabrous, smooth (not shagreen), ovoid, 5-6(-8) mm long, apex rounded with minute narrow style-remnant); valves 6; fruiting calyx smooth, not ridged, calyx lobes reflexed, hairy at apex within; fruiting pseudopedicel 4-5 mm long.

Figures

FIG. 4. — Lagerstroemia densiflora W.J.de Wilde & Duyfjes, sp. nov., Magnein 27 (P05179657): A, habit of flowering twig; B, detail of inflorescence; C, flower bud; D, flower; E, stamen; F, G, capsule with fruiting calyx, note calyx lobes hairy within; H, seed. Scale bars: A, 2 cm; B, 4 mm; C, D, F-H, 2 mm; E, 1 mm.