Phyllagathis lii C.W. Lin, C.F. Chen & T.Y.A. Yang, 2017

Lin, Che-Wei, Chen, Chien-Fan & Yang, T. Y. Aleck, 2017, Ten new species of Phyllagathis (Trib. Sonerileae, Melastomataceae) from Sarawak, Borneo, Phytotaxa 302 (3), pp. 201-228 : 206

2. Phyllagathis lii C.W. Lin, C.F. Chen & T.Y.A. Yang , sp. nov. ( Fig. 4 , 5 ).

Type: MALAYSIA. Borneo, Sarawak, Sri Aman Division, Lubok Antu, Batang Ai, 180–300 m elev. Type specimen pressed from plants cultivated in a nursery in Taiwan, 9 July 2014, C. W. Lin 574 (holotype TAIF)

Diagnosis: Phyllagathis lii resembles P. beccariana ( Cogniaux 1891:467) Nayar (1976: 231) in its habit, obovate leaf and umbelliform inflorescences, but differs from it in the not peltate leaf (vs. peltate or subpeltate), leaves up to 13 cm long (vs. up to 20 cm); shorter peduncle (2.8–4.7 cm vs. up to 20 cm) and densely puberulous inflorescence (vs. glabrous), with bracts 2–4 mm long (vs. 8 mm long); and hypanthium appressed puberulous (vs. glabrous).

Creeping or low erect herbs, terrestrial. Stems usually unbranched, olive, 3–7 cm long, 0.3–0.5 cm diameter, rooting at nodes with short erect upper stem 1–5 cm tall, terete, slightly woody at base, internodes 0.2–1 cm long, densely appressed pale-brown strigose, then glabrescent; sometimes sending out stolons up to 15 cm or longer, internodes 2–5 cm long. Leaf blades 2–6, decussate, rosetted, equal or subequal, obovate to obovate-elliptic, 8–13 × 4–8 cm wide; base cordate, sometimes slightly auriculate, apex obtuse to acute, margins with rows of appressed pale-brown strigose trichomes; thick chartaceous; venation acrodromous, ca. 7 veined, 1 primary vein and 1 pair of suprabasal secondary veins, often symmetrical at union with midvein, produced ca. 5 mm from the leaf base, positioned 0.9–1.8 cm in from margin at widest part of blade; adaxial surface dark olive to blackish, glossy, glabrous except on the veins, appressed velutinous on main veins, densely towards the base; abaxial surface pale magenta, densely appressed puberulous on all veins. Petioles 0.5–1.5 cm long, transversely elliptic, grooved above, densely appressed pale-brown strigose. Bracts persistent, chartaceous, lanceolate, green, 2–4 × 0.5 mm at the base of the inflorescence and becoming smaller upwards. Inflorescences in the upper leaf axils, umbelliform, peduncle 2.8–4.7 cm long, reddish, appressed puberulous. Flowers tetramerous, pedicels 5–7 mm long, sparsely to densely appressed puberulous. Hypanthium campanulate, subquadrangular, ca. 3 mm long, 3 mm diam., appressed puberulous and with sparse glands. Sepals 4, persistent, widely triangular, connate into a rim, each lobe with an acute-angled, triangular keel, ca. 0.5 mm long. Petals 4, oblique, ovate to widely ovate, sometimes obovate, 4.5–6 × 3 mm, white, pinkish at apex, glabrous, apex apiculate. Stamens 8, isomorphic, subequal, filaments slightly flat, 3–4.5 mm long, white to magenta, anthers narrowly lanceolate, apex attenuate, ventrally curved, 3–4.5 mm long, purplish to bluish, pore 1, connective distinct, ventrally with one pair of inconspicuous tuberculate appendages on base of anther sacs, dorsal appendage lacking or inconspicuously tuberculate. Style filiform, pale magenta, 6.5–8 mm long, glabrous, stigma capitate. Ovary ca. 1/2 as long as the hypanthium, crown lobes large, with fully connate lobes, margins denticulate, anther pockets shallow, placentae stalked. Capsules on pedicels to 9 mm long, hypanthium cup-shaped, subquadrangular, 8-ribbed, 4–4.5 × 3.5–4 mm, placentae disintegrating after seed dehiscence.

Distribution and ecology: Endemic to Batang Ai area in western Sri Aman Division, Sarawak ( Fig. 3 ). It grows on steep slopes of a narrow gorge in lowland mixed dipterocarp forest, at 180 to 300 m elevation.

Etymology: The specific epithet is named in honor of Mr. Weng-Feng Li, who grows this Phyllagathis and provided the specimens for our studies.

Figures

FIGURE 3. Distribution maps of Phyllagathis lii, P. millelunata, P. rivularis, P. rubrosetosa, P. ulu, (stars); P. phyllioides, P. violinifolia, P. yodae (solid circles); P. bicolor (solid triangles); P. wallacei (solid squares) in Sarawak, Borneo.

FIGURE 4. Phyllagathis lii C.W. Lin, C.F. Chen & T.Y.A. Yang. A. Habit; B. Adaxial leaf surface; C. Abaxial leaf surface; D. Bracts, adaxial view; E, E’. Flower, face and side views; F. Petal, abaxial view; G, G’, G’’. Stamens, ventral, side and dorsal view; H. Style; I. Hypanthium, side view; J. Vertical section of ovary.All from C.W. Lin 574 (TAIF).

FIGURE 5. Phyllagathis lii C.W. Lin, C.F. Chen & T.Y.A. Yang. A. Habit and habitat; B. Adaxial leaf surface; C. Abaxial leaf surface; D. L eaf base and petiole; E. Inflorescences; F. Immature inflorescence; G. Flowers; H. Stamens, side view; I. Hypanthium; J. Capsules. B–G from C.W. Lin 574 (TAIF).