Paralasianthus zhengyianus H. Zhu, 2015

Zhu, Hua, 2015, Paralasianthus (Rubiaceae), a new genus from Southeast Asia, Phytotaxa 202 (4), pp. 273-278 : 275

2. Paralasianthus zhengyianus H. Zhu , sp. nov. ( Fig. 1 )

A P. dichotomo (Korthals) H. Zhu simile, sed pedunculis 1–2 mm longis, foliis lanceolatis nitidis 1.5–2 cm latis, apice mucronatis, venae secundarieae et tertiariae supra et subtus proeminentibus differt. A P. brevipes H. Zhu foliis lanceolatis 1.5–2 cm latis coriaceis basi angusti-cuneatis apice mucronatis, nervis 5–6 binatis differt.

Type:— PHILIPPINES. Mindanao: Mt. Candoon, s.d., BS 38840 (M. Ramos & G. Endano) 0310376 (Holotype L (L 0310376).

Shrubs or treelets, glabrous; branchlets terete or compressed in the youngest part, c. 1.5 mm in diam. Stipules very small, subulate ca. 1 mm long; colleters on the inside base of the stipules. Petioles ca. 5 mm long; leaf blades lanceolate, 6–8 × 1.5–2 cm, coriaceous, nitid on both surfaces, the base narrowly cuneate, the apex mucronate; midribs, secondary and tertiary venation prominent on both surfaces; secondary veins 5–6 on each side of midrib, ascending at an angle of 45–50˚, curved toward the leaf margin, joined near the margin and forming a looped venation; tertiary venation reticulate. Inflorescences cymose, pedunculate; peduncles 1–2 mm long; bracts and bracteoles very small, subulate, less than 1 mm long. Flowers pedicellate; pedicels slender, ca. 2 mm long. Calyx obconical-campanulate, glabrous, tube obconical-campanulate, 1 mm long, ca. 1 mm long, with 4 minute teeth. Corolla tubular, glabrous outside. Immature drupes compressed, ovoid, verrucose; pyrenes 2, with thin walls.

Distribution —Endemic to the Philippines.

Notes:—This species differs from P. dichotomus in having short peduncles (1–2 mm long), lanceolate and nitid leaves, which are less than 2 cm broad, and mucronate at the apex, and distinct venation, prominent on both surfaces. It differs from P. brevipes in having lanceolate and coriaceous leaves, with 5–6 secondary veins on each side of midrib.

Figures

FIGURE 1. Paralasianthuszhengyianus H.Zhu.1.Habit with inflorescences.2.Enlarged nodeshowing stipuleand axillary inflorescence. 3. Calyx with pedicel. 4. Fruit. 5. Cross section of fruit. (from BS 38840 (M. Ramos & G. Endano) (holotype L). Drawn by Wu Xinning.