Polyosma scyphocalyx 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 : 85

29. Polyosma scyphocalyx Schulze-Menz ex B.J.Conn & O.K.Paul , sp. nov. — Fig. 15

Etymology. The specific epithet ( scyphocalyx ) of this new species refers to the cup-like (scypho­) calyx (- calyx) of this species.

Polyosma scyphocalyx is morphologically most similar to P. dentata , but it differs by its elliptic leaves (vs broadly elliptic for P. dentata ); glabrous, terminal inflorescence (vs sparsely hairy and axillary in P. dentata ); and by being a larger tree (6–15 m high) compared to P. dentata (4–6.8 m high). — Type: R. Hoogland 7414 & R. Schodde (holo LAE [ LAE 38504]; iso CANB [CANB85688.1, CANB85689.1],L [L 0035112], Papua New Guinea, Western Highlands, Lagaip Valley, 12 Aug. 1960.

Tree, 6–15 m tall, bole up to 4.5 m, 6–14 cm diam. Branchlets glabrous, brown, pustules grey, scattered. Leaves glabrous; petiole 1–3 cm long; lamina elliptic, 3.5–10 by 1.5–4 cm, coriaceous, both surfaces drying light brown; base acute, margin serrate, apex acuminate; secondary veins 9–22 on each side and an angle greater than 45° from midrib, regularly looping near margin onto the next secondary vein; tertiary veins weakly percurrent, glabrous, prominent on abaxial surface. Inflorescence racemose, terminal, <20-flowered; rachis 4–10 cm long, glabrous; flowers loosely and evenly clustered on distal half of rachis; pedicels 5–7 mm long; bracteoles 1–3 mm long, hairy. Calyx distinctly cup-shaped; calyx lobes 1–5 mm long. Corolla buds tubular, (5–) 13–25 mm long, reddish purple or greenish purple; corolla moderately hairy, remaining tubular at anthesis, except opening with 4 small lobes distally. Fruits ovoid, 9–13 by 5–9 mm, glabrous, green turning purplish blue or brown.

Distribution — Papua New Guinea (Madang, Morobe, Western Highlands, Eastern Highlands, Southern Highlands, Central, Milne Bay, Bougainville).

Habitat & Ecology — Occurring in montane forest from elevations of 2 400–3 150 m.

Conservation status — This widespread species is not regarded as endangered.

Additional specimens examined (Paratypes). PAPUA NEW GUINEA, Madang, Kaironk Village, G. Weiblen 991, M. Evans, B. Isua & S. Majneb ( LAE ); G. Weiblen 1052 ( LAE ); Morobe, Kabum, K.A. McElhanon 69 ( LAE ); Near Arigenang, Finschhafen Sub-District, D.B. Foreman NGF 48121 (L, LAE ); Lake Trist, E.E. Henty NGF 29019 (L, LAE ); Meri Creek, C.E. Ridsdale NGF 30326 ( LAE ); Western Highlands, Sirunki, D. Walker ANU 7419 (L [incorrectly labelled ANU 749], LAE ); Lagaip, R. Hoogland 7652 & R. Schodde (L, LAE ); Mt Giluwe, M. Coode & P. Waring NGF 32508 (K, L, LAE ); Tambul, M. Coode & P. Katik NGF 32953 (K, LAE ); Kubor Range, R. Pullen 5233 & 5293 (L, LAE );Tomba, J.­F. Veldkamp 5447 & P.F Stevens (L, LAE ); Eastern Highlands, Mt Wilhelm, J.C. Saunders 787 (L, LAE ); Okapa, T.G. Hartley 13087 ( LAE ); Marafunga, P.F. Stevens LAE 51004 (L, LAE ); Kassam Pass, E.E. Henty & J. Vandenberg NGF 29319 (L, LAE ); Southern Highlands, Mt Bosavi, K. Damas LAE 58879 (BRI, CBG, L, LAE ); Tari, C. Kalkman 4886 (K, L, LAE ); Mt Ne, C. Kalkman 4918 (L); Tari, C. Kalkman 5159 & 5174 (K, LAE ), A. Gillison NGF 25135 (K, LAE ); A. Gillison NGF 25138 (K, L, LAE ); D. Frodin NGF 28128 (K, L, LAE );Ibiwara, D. Frodin NGF 28356 ( LAE ); Kagaba- Mendi, J. Vandenberg, P. Katik & A. Kairo NGF 40095 (K, L, LAE );Mt Ambua, W. Vink 17229 & 17463 (L, LAE ); Central,Woitape, A.N. Millar 1232 (L, LAE ); Mt Gerebu, S.A James 1438 ( LAE ); Northern,Kokoda, J.R. Croft LAE 65009 (L, LAE ); Milne Bay, Mt Suckling, P.F. Stevens & J.­F. Veldkamp LAE 54965 (L, LAE ); Baniara, A. Kanis 1230 (L, LAE ); Fergusson Island, J.R. Croft LAE 71075 (L, LAE ); Bougainville: Pavariri, C.E. Ridsdale & P. Lavarack NGF 31018 (L, LAE ).

Notes — 1. Although P. scyphocalyx is morphologically also like P. rampae , it is readily distinct from the latter shrubby species ( P. rampae c. 2 m tall). When compared with P. rampae (not included in morphometric analyses), P. scyphocalyx has elliptic leaves, with petiole 1–3 cm long, lamina 3.5–10 cm long, and apex acuminate, distinguishing it from P. rampae that has narrowly obovate smaller leaves (petiole 0.4–1.2 cm long, lamina up to 2.7 cm long), and apex acute and mucronate. The inflorescence rachis is longer in P. scyphocalyx (4–10 cm long, vs 1.5–2 cm long in P. rampae ).

2. Furthermore, the cup-shaped calyx readily distinguishes P. scyphocalyx from the tubular calyces of both P. dentata and P. rampae .

Figures

Fig. 15 Isotype collection of Polyosma scyphocalyx Schulze-Menz ex B.J.Conn & O.K.Paul, sp. nov., showing leaves and flowers (R. Hoogland 7414 [CANB85688.1]). a. Insert showing closeup of leaves and fruits [CANB85689.1]).