Begonia yapenensis M.Hughes, 2015

Hughes, Mark, Barber, Sadie, Heatubun, Charlie D. & Gagul, Janet, 2015, Begonia yapenensis (sect. Symbegonia, Begoniaceae), a new species from Papua, Indonesia, European Journal of Taxonomy 119, pp. 1-6 : 2-4

Begonia yapenensis M.Hughes sp. nov.

urn:lsid:ipni.org:names:77145852-1

Figs 1–2

Type

INDONESIA. Cultivated collection 20 Aug. 2014, Barber SBAR86 (holo-: BO; iso-: E, MAN). Cultivated in the Royal Botanic Garden Edinburgh from vegetative material collected in the wild (Accession 20090830: Indonesia, Papua Province, Yapen Island, Ambaidiru, 1000 m, 18 Feb. 2009, Argent, Barber, Ensoll & Galloway ABEG211).

Description

Sprawling much-branched caulescent herb to 20 cm high. Stem green, becoming woody at the base, internodes 3–5 cm long, pilose with 3 mm long white hairs. Stipules persistent, glabrous, narrowly triangular, caudate, 15–18 × 4–6 mm. Leaves: petiole ca. 5 mm, pilose; lamina lanceolate, asymmetric, 8–10 × 2.5–4 cm, midrib 7–9 cm, basifixed, base cordate, lobes not overlapping; upper surface rugose, green with purple-red veins, shortly hispid between veins, hairs ca. 1 mm; underside paler than upper surface, shortly hispid on veins only; venation pinnate palmate; margin biserrate; apex acute-attenuate. Inflorescence terminal, total length 3–5 cm, cymose, compressed at first and becoming more elongate at maturity, unisexual or bisexual, protogynous, female flowers solitary or in pairs, basal, male flowers ca. 10–15; primary peduncle 3–13 mm, shortly hispid; secondary peduncles shorter and glabrous; bracts 7–11 × 2–4 mm, linear-lanceolate, apex acute, white, glabrous. Male flower: pedicel 4–12 mm, white, shortly hispid; tepals 2, rhombic-ovate, fused just under half way, 10–13 × 8–10 mm, white, shortly hispid at base, base bulbous, apex acute; androecium with 6–9 stamens, basal 5 subsessile, remainder on a thick 1mm long column; filaments 0.5 mm long, white; anthers 1 mm long, burgundy, ellipsoid, pollen white. Female flower: pedicel 4–7 mm, pale green, shortly hispid, bracteoles present; ovary whitish green, total size 10 × 19 mm including wings, wings 3, subequal, triangular, up to 10 mm long, margin hispid; capsule ellipsoid, 8 × 5 mm, sparsely hispid, placentae 2 per locule; tepals 5, corolla tubular, ca. 18 × 8 mm, petals fused for ca. ¾ of the length, white, shortly hispid, hairs denser near the base, lobes ca. 5 mm long, apex acute; stigmas 3, on a 1 mm style, length 7 mm, forked for ⅔ of the length, spirally twisted twice, pale yellow. Fruit on a stiff ca. 5 mm pedicel, total size including wings 11 × 21 mm.

Distribution

Indonesia. Only known from the type locality in central Yapen Island, Papua Province ( Fig. 2 ).

Habitat

Collected in the forest around Ambaidiru village, away from disturbed areas on relatively unspoilt steep mountain sides with orange clay soil and large limestone boulders, near the top of the mountain at ca. 1000 m, in an Agathis grove showing signs of tapping for resin on the trunks. Understory vegetation in the area consists of Marattia Sw. , Angiopteris Hoffm. , Laportea Gaudich. , Zingiberaceae Martinov , Aeschynanthus Jack , Begonia , Cyrtandra J.R.Forst. & G.Forst. , Pandanus L.f., Davallia Sm. and Selaginella P.Beauv.

Notes

Begonia yapenensis sp. nov. appears to be closest to Begonia sympapuana (Merr. & L.M.Perry) L.L.Forrest & Hollingsw. ( Merrill & Perry 1943: 59; Forrest & Hollingsworth 2003: 208), which shares the rugose leaves with reddish veins and broadly similar inflorescences and flowers. Begonia yapenensis sp. nov. differs in being a smaller, lower growing plant with shorter internodes and a white undumentum (not reddish), the leaves having shorter petioles (ca. 5 mm, not 1–1.5 cm), male flowers with tepals fused halfway (not shortly fused at the base) and fewer stamens (6–9, not ca. 15) which are arranged along a short column (not arising from a short torus), and fruits which have more attenuate wings. Plants of B. yapenensis sp. nov. in cultivation in deep shade show a blue iridescence of the upper leaf surface.

Conservation status

Data Deficient (DD; IUCN 2012). The conservation status of B. yapenensis sp. nov. is not known. The distribution and habitat information for this species is based on just one collection from Ambaidiru village in the highlands of Yapen Island, Papua, Indonesia. Although the forest around Ambaidiru village is part of the Central Yapen Natural Reserve, the establishment of road access from south to north across the island within the protected area, as well as the expansion of Ambaidiru village, may affect the population of this Begonia . More population and distribution data are required to fully assess the conservation status of this species.

Figures

Fig. 1. Begonia yapenensis M.Hughes sp. nov., cultivated specimen at the Royal Botanic Garden Edinburgh, accession 20090830. A. Whole plant showing spreading habit (scale bar = 5 cm). B. Female flower and ovary (left, corolla dissected; right, corolla entire) (scale bar = 1 cm). C. Cross section of ovary showing three locules with bilamellate placentae (scale bar = 1 cm). D. Stigmas (scale bar = 5 mm). E. Male flower (bottom, corolla dissected; upper, corolla entire; scale bar = 10 cm).

Fig. 2. Map of Tanah Papua, Indonesia, showing the distribution of Begonia yapenensis sp. nov. on Yapen Island, and of the allied Begonia sympapuana in the mountains at the head of the Idenburg River.