Polyosma heliciiformis Kaneh. & Hatus.

Paul, O. K., Conn, B. J. & Henwood, M. J., 2024, Taxonomic review of Polyosma (Escalloniaceae) in Papuasia, Blumea 69, pp. 54-88 : 71-73

13. Polyosma heliciiformis Kaneh. & Hatus.

Polyosma heliciiformis Kaneh.& Hatus. (1942) 305,f. 2 (‘ heliciaeformis ’). — Type: R. Kanehira & S. Hatusima 12333 (holo FU, n.v.; probable iso A [ A42993 ]), Indonesia Papua, Geelvink Bay , Patema , “ 40 km inward from Nabire” ( Kanehira & Hatusima 1942: 307), ‘ 5 Mar. 1940 ’ and ‘ 5 May 1940 ’ (respectively).

Typification. The collection date of the replicate type material, as held at

A (‘ May 5, 1940 ’) is here regarded as a probable labelling error .

Shrub to 3 m tall. Branchlets tomentose with brown hairs. Leaves sparsely hairy abaxially, glabrous adaxially; petiole 1–2 cm long; lamina rhombic-oblong or narrowly obovate, 10–20 by 3–6 cm; base attenuate to narrowly cuneate, margin remotely crenulate-denticulate, apex acuminate; secondary veins 7–11 on each side and at 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, subterminal, rachis 4 –5 cm long, hairy; bracteoles hairy. Calyx lobes c. 1.7 mm long. Corolla buds tubular, c. 12 mm long, white, with dense greyish hairs. Fruits ovoid, 13–15 by 5–7 mm, glabrous, blackish purple.

Distribution — Only known from the type material collected in West New Guinea ( Indonesia Papua).

Habitat & Ecology — Recorded from ‘rain-forests at about 400 m altitude’ ( Kanehira & Hatusima 1942: 307), but the (probable) isotype, Kanehira & Hatusima 12333, as held at A, records the elevation as ‘Altitude above sea level 300 m’ .

Conservation status — The conservation status of this species is unknown.

Nomenclature — The specific epithet provided by Kanehira & Hatusima (1942) (‘ heliciaeformis ’) consisted of two elements that were not combined correctly ( Turland et al. 2018: Art. 60.10), and is corrected to ‘ heliciiformis ’.

Notes — Kanehira & Hatusima (1942: 307, f. 2) described and illustrated the inflorescence of this species as ‘subterminal’. Their illustration suggests that the rachis arises laterally from a terminal inflorescence axis. Since additional specimens of this species are not known, the structure of the inflorescence cannot be investigated further.

This species is morphologically similar to P. dentata and P. helicioides ; however, it differs by being a shrub c. 3 m tall (vs tree 4–6.8 m tall in P. dentata ; tree 6–10 m tall in P. helicioides ); branchlets tomentose with brown hairs, without pustules (vs branchlets glabrous, brown with scattered pustules in P. dentata ; branchlets glabrous to slightly hairy, brown, with pustules in P. helicioides ); leaves sparsely hairy (like P. helicioides ) (vs glabrous in P. dentata ); lamina rhombic-oblong or oblanceolate, 10–20 cm long (vs lamina broadly elliptic, 5.5–11.5 cm long in P. dentata ; lamina elliptic, 5–22 cm long in P. helicioides ); secondary veins 7–11 on each side (vs secondary veins 13–19 on each side in P. dentata ; secondary veins 11–25 on each side in P. helicioides ); and inflorescence subterminal (vs axillary in both other species).