Polyosma kamialiensis 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 : 76-78

18. Polyosma kamialiensis B.J.Conn & O.K.Paul , sp. nov. — Fig. 10 , 11

Etymology. The specific epithet of this new species ( kamialiensis ), refers to the Kamiali area,near the village of Lababia ( Papua New Guinea, Morobe Province) where this species is known to occur.

Polyosma kamialiensis is morphologically similar to P. pubescens but differs from the latter by having leaves with lamina elliptic to slightly obovate, 11–25 by (4–) 5–8 cm, with 17–28 secondary veins on each side of the midrib (vs P. pubescens that has elliptic leaves, 9–11 by 3.5–4.5 mm, with 10–15 secondary veins). — Type: B.J. Conn 5232, O.K. Paul, D.J. Damas & S.B. Sennart (holo NSW [NSW772015]; iso LAE [ LAE 209120]), Papua New Guinea, Morobe, Kamiali Wildlife Management Area,S of Kamiali Guest House, 21 May 2009.

Polyosma forbesii auct.non Valeton ex Lauterb.: Conn & Damas (2019) f. 416.

Erect subcanopy tree, 10–15 m tall; trunk cylindrical, dbh 15–17 cm; bole straight, up to 5–10 m long, moderately to coarsely ridged, fluted at base or buttresses-like, with buttressing up to 40 cm high; outer bark brown, rough, slightly fissured, pustular, with lenticels irregular; subrhytidome red; bark 5–10 mm thick; inner bark 1-layered, strongly aromatic, unpleasant; pale to dark red, with stripes (sometimes indistinct), fibrous; exudate colourless, not readily flowing, colour not changing and not sticky. Branchlets hairy, pale brown, with spreading off-white hairs. Leaves: petiole 1.5–2(–2.8) cm long, densely hairy, like branchlets; lamina elliptic to slightly obovate, 11–25 by (4–) 5– 8 cm, subglossy, dull pale green abaxially, green to dark green adaxially, coriaceous, rough, densely hairy on abaxial surface and along midvein on adaxial surface; base acute, margin entire, apex ± attenuate; secondary veins dull yellow-green, 8–10 on each side of midrib and at an angle greater than 45° from midrib, regularly looping near margin onto the next lateral vein; tertiary veins weakly percurrent, densely hairy, prominent on abaxial surface. Inflorescence racemose, axillary, erect (young inflorescence pale green),> 30-flowered; rachis (5–)7–13(–18) cm long, hairy; flowers clustered together; pedicels (3–) 4–8 mm long; bracteoles (1–) 2–6.8 mm long, hairy. Calyx lobes 1–3 mm long. Corolla buds tubular, 10–20 mm long, white to pale yellow, often with greenish tinge; corolla densely hairy, remaining tubular at anthesis, except opening with 4 small lobes distally. Fruits ovoid or globular, 5–10 by 4–8 mm, smooth, green with slight maroon tinge (when immature), maturing to blackish purple, moderately hairy, with hairs antrorse.

Distribution — Endemic to the Kamiali area of Morobe Province of Papua New Guinea.

Habitat & Ecology — Occurring in open secondary mixed alluvial, lowland to lower montane forest. Growing on rich humic clayey soils.

Conservation status — Although this species is restricted to a small area, since it is included in the Kamiali Conservation Management Area, it is afforded some protection.

Vernacular name — Tar (Kela language; Informant: Tanny Gei).

Uses — Wood used by local people for building houses.

Additional specimens examined (Paratypes). PAPUA NEW GUINEA, Morobe, Kamiali Conservation Area, Baudu, near Alalo 2 Creek, B.J. Conn 5571, K.Q. Damas, D.J. Damas & B.G. Sule ( LAE, NSW ); Allen Allison Track, c. 100 m W of Araro 1 River, 1.7 km W of Lababia Village, B.J. Conn 5804, K.Q. Damas, K.M. Fazang & O.K. Paul (LAE, NSW) ; trail to Cliffside from Kamiali Guest House, O.K Paul & S.A. James SAJ133 (NSW); O.K. Paul & S.A. James LAE 87544 (L); Bulili ridge near Lababia, W. Takeuchi 14329, 15090 ( LAE ); ridge to Cape Roon, slopes above Ariwiri river, Lababia, W. Takeuchi 14884, 14894 & A. Towati (CANB, L, LAE );near Tabare (Tabali) river, Lababia, W. Takeuchi 15413, D. Ama & A. Towati ( LAE ); ridge to Blue Mountain, near the Nembebah bivouac, W. Takeuchi 21047 ( LAE ).

Notes — 1. Polyosma kamialiensis shares several morphological similarities with P. pubescens and P. schulzemenzii (all Papuasian species), all having hairy leaves with margin entire, and apex attenuate. Apart from the differences mentioned in the diagnosis (above), P. kamialiensis has leaves and rachis that are densely hairy, with hairs retrorse to reflexed compared to P. pubescens that has leaves and rachis sparsely hairy with spreading hairs. The white to pale yellow corolla of P. kamialiensis also differs from the pinkish green corollas of P. pubescens .

2. The morphological differences that readily distinguish this new species from P. schulzemenzii include bracteole length ( P. kamialiensis usually 2–6.8 mm long vs 5–10 mm long in P. schulzemenzii ), white to pale yellow corollas (vs greenish brown in P. schulzemenzii ), and leaf lamina with base acute (vs rounded in P. schulzemenzii ).

Figures

Fig. 10 Polyosma kamialiensis B.J.Conn & O.K.Paul, sp. nov. a. Distal end of leafy branchlet showing adaxial leaf surface; b. leaf showing indumentum on petiole, and on midvein and secondary veins of abaxial surface; c. detail of abaxial surface of leaf showing distinct indumentum on midvein and secondary veins, with scattered hairs on lamina surface; d. developing inflorescence with flowers in bud, showing hairy bracteoles and calyces; e. developing (immature) fruit densely covered in hairs. — Scale bar (for each of the labeled illustrations): a = 120 mm; b = 60 mm; c = 4 mm; d = 9 mm; e = 15 mm (all: B.J. Conn 5232, O.K. Paul, D.J. Damas, S.B. Sennart, L.J. Murray & K.M. Downs [NSW772015]). — Drawing by Catherine Wardrop (NSW).

Fig. 11 Holotype collection of Polyosma kamialiensis B.J.Conn & O.K.Paul, sp. nov., showing branchlet with leaves and developing fruits (B.J. Conn 5232, O.K. Paul, D.J. Damas, S.B. Sennart, L.J. Murray & K.M. Downs [NSW772015]).