Polyosma glaberrima Schulze-Menz ex B.J.Conn & O.K.Paul, 2024

Paul, O. K., Conn, B. J. & Henwood, M. J., 2024, Taxonomic review of Polyosma (Escalloniaceae) in Papuasia, Blumea 69, pp. 54-88 : 71

12. Polyosma glaberrima Schulze-Menz ex B.J.Conn & O.K.Paul , sp. nov. — Fig. 8

Etymology. The specific epithet ( ‘ glaberrima ’) refers to the glabrous branchlets, leaves and fruits that characterize this species.

Polyosma glaberrima is morphologically most similar to P. gigantea with both having glabrous, acuminate leaves; however, P. glaberrima has an entire leaf margin, whereas P. gigantea has a leaf margin with an occasional small tooth, rarely entire. — Type: L.J. Brass 25739 (holo K; iso L [L 1871121]), Papua New Guinea, Milne Bay,Normanby Island,Mt Pabinama, 5 May 1956.

Subcanopy tree c. 12 m tall, bole c. 2.5 cm diam. Branchlets glabrous, black with scattered lenticels. Leaves glabrous; petiole 1.5–3 cm long, light brown; lamina obovate, 5–12 by 3–7 cm, thickly coriaceous, discolours in dried materials, yellowish brown adaxially, brown abaxially; base acute, margin entire, apex acuminate; secondary veins 8–18 on each side of midrib and at an angle greater than 45° from midrib, looping near margin onto the next secondary vein; tertiary veins weakly percurrent, not prominent on abaxial surface. Flowers not seen. Infructescence racemose, terminal, with fruits loosely and evenly arranged; fruiting rachis c. 6 mm long, with <20 fruits per rachis, glabrous; fruiting pedicels 7–10 mm long. Fruits ovoid, 6–13 by 4–8 mm, glabrous, green (immature).

Distribution — Papua New Guinea (Western Highlands, Central and Milne Bay).

Habitat & Ecology — Recorded from tall moss-forest at an elevation of 850 m.

Conservation status — Not known.

Additional specimens examined (Paratypes). PAPUA NEW GUINEA, Western Highlands,Tambul, M.Coode NGF 40023 ( LAE );Central,Lake Myola, J.R. Croft & Y. Lelan NGF 34819 (L, LAE ); Milne Bay, Normanby Island, M.A. Benjamin LAE 67860 (L, LAE ).

Notes — 1. Polyosma glaberrima also differs from P. gigantea by having obovate, broader leaves (3–7 cm wide vs leaves elliptic and 2–3 cm wide in P. gigantea ).

2. Polyosma glaberrima is also morphologically like P. mucronata and P. stenosiphon , with all three species having a glabrous abaxial leaf surface (or with only an occasional hair). It differs from P. mucronata by having variously obovate leaves, with petiole much shorter than lamina length (both characteristics shared with P. stenosiphon ), whereas P. mucronata has elliptic or narrowly ovate leaves, with petiole almost as long as the lamina. Polyosma glaberrima is readily distinguished from P. stenosiphon by the former species having mostly larger leaves (5–12 cm long, 3–7 cm wide) and longer petioles (1.5–3 cm long), whereas P. stenosiphon has leaves 4 – 6 cm long, 1.3–2(–3) cm wide, and petiole 0.7–1 cm long.