Monoon pachypetalum I.M.Turner & Utteridge, 2017

Turner, Ian M. & Utteridge, Timothy M. A., 2017, Annonaceae in the Western Pacific: geographic patterns and four new species, European Journal of Taxonomy 339, pp. 1-44 : 3-5

Monoon pachypetalum I.M.Turner & Utteridge sp. nov.

urn:lsid:ipni.org:names:77164167-1

Figs 1–2

Diagnosis

Differs from the other described species of Monoon from Melanesia in its relatively short and thick flower pedicels and broadly ovate, thick fleshy petals. Differs from Monoon salomonicum sp. nov. in having a distinctly asymmetric leaf base and subsessile monocarps.

Etymology

We maintain the epithet chosen by Diels which reflects the thick petals of the new species.

Type

INDONESIA: Papua, Nordküste, Mittellauf des Tor-Flusses , 11 Oct. 1911, K. Gjellerup 738 (holo-: B10 0365021 ; iso-: K000691685).

Additional specimens examined

INDONESIA: Papua, SE West Irian, Mindip Tanah, along Imko River, 3 Jun. 1971, Nedi 781 ( K); West Papua, NE Kepala Burung, Kabupaten Manokwari, Nuni, Sungai Asia, 15 Aug. 1995, J. Dransfield JD7565 ( K [2 specs]).

Description

Tree to at least 10 m tall, 10 cm dbh. Twigs drying blackish or dark brown, longitudinally wrinkled, sometimes with small brown, round or oval lenticels; youngest parts with pale brown tomentum, otherwise glabrous. Leaves chartaceous, drying grey-brown above, brown or grey-brown below with darker brown midrib and lateral nerves, midrib slightly sunken above in dry leaves, prominent below, lateral nerves more or less flush above, raised below, glabrous or sparsely hairy along midrib above, glabrous or with scattered hairs on nerves below, lamina ovate-elliptic to obovate, 7–21 × 2.5–8 cm, apex shortly acuminate, base obtuse to cordate, distinctly asymmetric with one side more markedly lobed, lateral nerves 9–12 pairs, arching forward and running more or less parallel before looping obscurely just within margin, intersection of laterals with midrib decurrent, tertiary venation scalariform, distinct from both surfaces in dry leaves; petioles 4–6 mm long, drying blackish, minutely wrinkled, sometimes with brown hairs. Inflorescences axillary, solitary, single-flowered. Flowering pedicel 7–15 mm long, 1–1.5 mm diameter, widening distally, drying dark brown, wrinkled, sparsely hairy; medial bract broadly ovate ca 1 × 2 mm, hairy outside, glabrous within; calyx connate forming 3-pointed cup, each sepal broadly ovate 2 × 4–5 mm, sparsely short brown hairy outside, glabrous, drying blackish, within; outer petals broadly ovate ca 13 × 10 mm, base truncate, apex acute, drying ca 1 mm thick in upper portion, externally verruculose but obscured by dense brown or pale adpressed tomentum, similar inside except for glabrous region near base; inner petals ovate-lanceolate ca 10 × 7 mm, brown tomentose except for basal part of adaxial surface which dries black, sometimes longitudinally grooved distally and warty proximally, otherwise smooth; stamens many in 4–5 rows, ca 1 mm long, connective apex polygonal; carpels many. Fruiting pedicel to 25 mm long, 2 mm thick, widening distally, drying brown, longitudinally striate, very short pale hairs, monocarps ca 10, drying dull dark brown with very short brown tomentum, ellipsoidal ca 2.5 × 1.5 mm, subsessile. Seeds 1.

Field notes

Bark dark grey, smooth (J. Dransfield JD7565); twigs blackish (J. Dransfield JD7565); leaves mid green (J. Dransfield JD7565); flowers yellow (Nedi 781); fruit pale yellowish green (J. Dransfield JD7565).

Distribution and habitat

Lowland forest in New Guinea ( Fig. 2 ).

Conservation status

Currently known from only three collection sites in Indonesian New Guinea: one on the south of the central range just to the north of Tanah Merah, one on the north coast near Sarmi and the other in the Vogelkop coastal area near Manokwari. All three sites appear to be relatively undisturbed when using Google Earth imagery, or close to undisturbed areas, and it is to be expected that Monoon pachypetalum sp. nov. is found in lowland forest throughout Indonesian New Guinea. Using the known collection data, it is difficult to accurately estimate the EOO using GeoCat because of large areas of unsuitable habitat (the high elevations of the central range and the Cendrawasih Bay). An approximate EOO is 55,400 km 2 (based on two polygons of 49,000 + 6,400 km 2 excluding unsuitable habitat and encompassing the collection sites) which is outside any of the IUCN threat criteria. However, the AOO is 12 km 2 which falls within the EN category and the species is also known from only three locations. However, because the habitat in the environs of the collection localities appears to be intact, we are currently unable to know if the quality of the habitat is declining, etc., and thus the species does not fulfil the two criteria for a geographic range assessment. We thus estimate Monoon pachypetalum sp. nov. as Near Threatened (NT) noting that further collection locations are needed, as well as better observations of population size and habitat quality.

Figures

Fig. 1. Monoon pachypetalum I.M.Turner & Utteridge sp. nov. A. Foliage. B. Shoot bearing flower in leaf axil. C. Shoot bearing old fruit without monocarps. D. Detached monocarp. E. Flower, lateral view. F. Flower pedicel and calyx viewed from below. G. Outer petal, abaxial view. H. Median longitudinal section through outer petal. I. Inner petal, abaxial view. Scale bars: graduated single bar = 5 mm; double bar = 1 cm; graduated double bar = 5 cm. Drawn from Dransfield JD7565 (A, C, D); Nedi 781 (B, E); Gjellerup 738 (F–I). Drawn by Andrew Brown.

Fig. 2. Map of New Guinea showing the collecting localities of Monoon pachypetalum I.M.Turner & Utteridge sp. nov.