Huberantha whistleri 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 : 12-14

Huberantha whistleri I.M.Turner & Utteridge sp. nov.

urn:lsid:ipni.org:names:77164169-1

Figs 7–8

Diagnosis

Similar to Huberantha amoena of Fiji but with broader leaves in absolute (4–6.5 cm vs up to 4 cm) and relative terms (length: breadth ratio of less than 3 vs 3–4), less slender flowering pedicel (0.75 vs 0.5 mm diameter), broader stamen connective apex (1.5 vs 0.5 mm), and longer stipes to the monocarps (12–15 vs 10–11 mm). Huberantha amoena appears habitually to have tiny hairy domatia in the axils of the lateral nerves on the abaxial lamina surface which are absent in the material of Huberantha whistleri sp. nov.

Eponymy

We are pleased to name this species in honour of W. Arthur (“Art”) Whistler, the discoverer of this and many other Pacific taxa.

Type

SAMOA: Savai’i, growing in the forest above Ologogo; elevation 600 m a.s.l., 23 Mar. 1973, A. Whistler 576 (holo-: K000607798; iso-: BISH0428621, BISH0711560, K000607799, NTBG).

Description

Tree 8 m tall. Twigs drying dark brown or grey-brown, longitudinally striate or with impressed lozenges, glabrous. Leaves membranous to chartaceous, glabrous, drying grey above with midrib pale brown, paler grey below with midrib dark brown, midrib slightly sunken above in dry leaves, prominent below, lateral nerves slightly raised on both surfaces, lamina oblong-ovate to oblong-lanceolate, 11–18 × 4–6.5 cm, apex acuminate, base obtuse to rounded, ultimately slightly decurrent to petiole, lateral nerves 9–12 pairs, initially running out at about 70˚ to the midrib then arching forward and looping some 1–4 mm within margin, tertiary venation reticulate and visible from both surfaces in dry leaves; petiole drying blackish or dark brown, 6–9 mm long, 1–1.5 mm thick, minutely wrinkled, glabrous. Inflorescences in axils of fallen leaves bearing 1 or 2 flowers at one time, peduncle 1–2 mm long with scattered short red-brown hairs. Flowering pedicel 17–20 mm, ca 0.75 mm thick, widening distally, drying dark brown, longitudinally striate and minutely pimpled; sepals broadly ovate-triangular ca 1 × 1.5 mm, red-brown hairy outside, glabrous within drying black-brown; petals linear lanceolate to slightly spathulate, 12– 20 mm long, 4–5 mm wide, with outer petals wider at base ca 2 mm vs 1 mm in inner petals, drying dark brown with short pale brown hairs; stamens many, ca 1.5 mm long, drying pale brown, connective apex flat, polygonal ca 1.5 mm diameter, minutely hairy; carpels many, ca 2 mm long, densely pale brown hairy, stigmas capitate, short hairy. Fruiting pedicel to 23 mm long, 2 mm wide, drying dark brown, minutely wrinkled and pimpled, monocarps to 16 or more, (immature) ellipsoidal ca 10 × 5 mm, drying dark brown to black, with scattered brown hairs, stipes 12–15 mm long, ca 1 mm wide.

Distribution and habitat

Samoa ( Fig. 8 ) in hill forest.

Conservation status

The species is currently only known from the northern slopes of Savai’i (we have not had access to the second sterile collection Whistler 9481a – above Sāsina in lowland forest at 270 m a.s.l.). Whistler (2011: 75) has noted that the species is “rare in lowland to foothill forest” in this location, but he gives no further information on the habitat or the population size. From Google Earth imagery, the habitat is disturbed in some areas on the north coast around Sasina (but this may be natural disturbance due to typhoons), but also shows some areas with complete tree cover, and with only two points we are unable to calculate an EOO; we therefore we give this species a preliminary conservation rating of Near Threatened (NT).

Figures

Fig. 7. Huberantha whistleri I.M.Turner & Utteridge sp. nov. A. Flowering shoot (lower right leaf showing abaxial surface, rest adaxial). B. Flower lateral view (one petal missing). C. Remnant flower with carpels and persistent calyx after loss of corolla and stamens. D, E. Two views of stamen. F. Ovary and stigma. G. Fruit (same scale as A). H. Monocarp (immature). Scale bars: graduated single bar = 2 mm; double bar = 1 cm; graduated double bar = 5 cm. Drawn from Whistler 576. Drawn by Andrew Brown.

Fig. 8. Map of Samoa showing the collecting localities of Huberantha whistleri I.M.Turner & Utteridge sp. nov.