Monday, February 24, 2020

[Botany • 2020] Medinilla vexillifer (Melastomataceae: Dissochaeteae) • An Elegant New Species from the Philippines

Medinilla vexillifer C.W. Lin & Rubite

in Lin & Rubite, 2020. 

Medinilla vexillifer C.W. Lin & Rubite (Melastomataceae) from the Philippines is a new species described and illustrated. It most resembles M. calcicola Merr., but differs in its shorter petioles that are 0.2−0.8 (vs. 1−2) cm long, lanceolate to ovate (vs. obovate) leaf lamina, cordate (vs. acute to acuminate) leaf base, upper leaf surface that is densely covered with brownish-yellow stellate and dendroid trichomes (vs. glabrous leaf surfaces), terminal or axillary (vs. only axillary) inflorescences, to 15 (vs. 2−2.5) cm long, and 4- or 5-merous (vs. 5-merous) flowers. This exquisite species has hairy leaves and apendulous inflorescence with bright pink bracts and white petals. The bracts are long-persistent and last for about five months, which may result in its high horticultural potential.

Keyword: Dissochaeteae, Medinilla, Melastomataceae, Luzon, new species, Philippines

Fig. 2. Medinilla vexillifer C.W. Lin & Rubite.
A, B, C. Habit; D. Stem; E. Leaf; F. Portion of leaf adaxial surface, showing stellate trichomes; G. Portion of leaf abaxial surface, showing dendroid trichomes; H. Dendroid trichomes; I. Secondary bracts; J, K. Calyx and secondary bracts; L. Flower; M. Hypanthium and secondary bracts; N. Cross section of an ovary; O. Seeds. B-O from C.W. Lin 676 (TAIF).

Fig. 1. Medinilla vexillifer C.W. Lin & Rubite.
A. Habit; B, B'. Part of leaf, adaxial and abaxial surfaces; C. Vestiture of stem; D. Stellate and dendroid trichomes; E. Inflorescence; F, G. Bracts and secondary bracts; H, H'. Flower, face and side views; I. I'. Stamens, ventral and side views; J. Hypanthium; K, K'. Calyx, showing 4 and 5-merous conditions; L. Cross section of an immature fruit; M. Fruit. All from C.W. Lin 676 (TAIF).

Medinilla vexillifer C.W. Lin & Rubite, sp. nov.

 Type: PHILIPPINES. Original locality not known; possibly from Luzon Island. 
Type specimen pressed from plants purchased from a floral market in Manila, Philippines and cultivated in a nursery in Taiwan, 25 Nov. 2018, C. W. Lin 676 (holotype PNH!; isotype SING!, TAIF!).

 Scandent multi-branched shrub up to 80 m long. Stem terete, internodes to 10 cm long, shorter on the distal branches; nodes rather thickened, knobby, with densely covered with brownish-yellow dendroid trichomes, glabrescent, bark becoming striate on older stems; young stems about 3 mm in diameter, green.

Distribution and ecology: The exact collection locality of Medinilla vexillifer is unknown; according to Mr. Tan (pers, comm., 2018), the new species has been imported to the Singapore from Manila in 2013 so we assume it originated Luzon Island in the Philippines. 

Etymology: The specific epithet refers to the many colorful and pendeulous inflorescences, resembling countless flag.

Che-Wei Lin and Rosario Rivera Rubite. 2020. Medinilla vexillifer (Melastomataceae: Dissochaeteae), An Elegant New Species from the Philippines. Taiwania. 65(2); 149-153.