Perilimnastes banaensis J.H.Dai, T.V.Do & Ying Liu, 2023

Dai, Jin-Hong, Van Do, Truong & Liu, Ying, 2023, Four new species of Perilimnastes (Sonerileae, Melastomataceae) from Vietnam, PhytoKeys 235, pp. 1-19 : 1

Perilimnastes banaensis J.H.Dai, T.V.Do & Ying Liu sp. nov.

Figs 9 , 10

Type.

Vietnam. Đà Nẵng: Hoa Ninh , Ba Na Hills, 1,360 m elevation, in forests on damp slopes near steam, 22 Nov 2019, Jin-hong Dai and Ying Liu 813 (holotype: PE; isotypes: A, SYS, VNMN) .

Diagnosis.

Resembles P. ovalifolia and P. setipetiola in having raphide crystals, hyaline hairs, somewhat elliptic leaf blade, and umbels with very short or no peduncle, but differs in the stems and petioles densely villous with brown hyaline uniseriate hairs (vs. stems densely retrorse hirsute, glabrescent, and petioles densely hirsute to setose in the former species, and stems pubescent with brownish-yellow stellate hairs and rarely also hyaline hairs, petioles with brownish-yellow stellate hairs when young and hispid with long bristles in the latter).

Description.

Shrubs to 60 cm tall, with raphides in all parts. Stems branched, prostrate at lower parts; branchlets obtusely 4-sided and densely villous with appressed, brown hyaline uniseriate hairs composed of much elongated cells and tipped with a brown glandular cell; older branches near terete and glabrescent; leafy distally and leafless proximally. Leaves opposite, equal to unequal in a pair; petiole 1.5-4.6 cm long, densely villous with appressed, brown hyaline hairs; leaf blade elliptic, 5.5-13 × 2.5-6.5 cm, thick papery, with minute brown glands when young on both surfaces, abaxially sparsely pubescent with appressed brown hyaline hairs, densely so along the veins, 3 or 5-veined, dark green adaxially, pale green abaxially, base acute to rounded, margin entire or sometimes inconspicuously minutely repand, apex short acuminate to acute. Inflorescences and flowers unknown. Infructescences terminal, umbellate, sessile, capsules 2-7, pedicel 5-13 mm long. Old capsules cup-shaped, ca. 5 × 5 mm, 4-sided; hypanthium 8-ribbed; crown enlarged enclosing an obpyramidal space; placental column unbeaked, 4-horned; placenta thready.

Phenology.

Old fruits in November.

Etymology.

The specific epithet is based on Ba Na hills, the type locality of this species.

Distribution.

Perilimnastes banaensis is currently only known from Ba Na Hills, Hòa Ninh, Đà Nẵng, Vietnam (Fig. 1 ). It occurs on damp slopes in forests often near streams, at 1,360 m elevation.

Figures

Figure 1. Distribution of Perilimnastes multisepala (triangle), P. setipetiola (square), and P. uniflora and P. banaensis (solid circle).

Figure 9. Holotype of Perilimnastes banaensis, Jin-hong Dai and Ying Liu 813 (PE). The inset shows raphides (as white oblong spots) on adaxial leaf surface under stereoscope. Scale bars: 5 cm, 1 mm (inset).

Figure 10. Perilimnastes banaensis A habit B a branch with old capsules C close-up of a branchlet D adaxial (left) and abaxial (right) leaf surfaces E a sessile infructescence F longitudinal section of an old capsule showing enlarged ovary crown and morphology of the placental column and placentas. Scale bars: 2 mm (F). All from Jin-hong Dai and Ying Liu 813 (A, PE, SYS).