Ochrosia fatuhivensis Fosberg & Sachet, Micronesica 8: 48 (1972)

Lorence, David H. & Butaud, Jean-Francois, 2011, A reassessment of Marquesan Ochrosia and Rauvolfia (Apocynaceae) with two new combinations, PhytoKeys 4, pp. 95-107 : 99-100

Ochrosia fatuhivensis Fosberg & Sachet, Micronesica 8: 48 (1972) Figs 1C, D

Type.

Marquesas Islands: Fatu Hiva: Oia [Ouia], c. 800 m, 19 Jan. 1922, F. B. H. Brown 886 (Holotype BISH-500706!).

Description.

Tree 10-14 m tall, trunk 15-20 cm in diam., branchlets glabrous, leafy twigs 2.5-7 mm in diam., bark wrinkled when dry, latex white. Leaves opposite on smaller branchlets, apparently ternate on larger branchlets; blades elliptic, 5.8-20.2 × 2.4-10.1 cm, base narrowly cuneate, apex shortly acuminate, glabrous, discolorous, when fresh dark green above, pale green below, drying brown, margins slightly revolute; secondary veins 9-20 on each side, prominulous on both surfaces, intersecondaries and tertiaries prominulous on both surfaces; petioles 14-36 mm long. Inflorescence terminal, tri- or quadrichotomous, branching twice, cymose-corymbiform, 52-88 mm long, axes and flowers glabrous, sessile, with 3 primary branches (6-)20-64 × c. 2 mm, subquadrangular, bracts ovate-triangular, 1-1.2 × 1-1.2 mm, ultimate axes with flowers crowded in cymules; flowers with pedicels 2-5 mm long, each with a single bract, calyx cup 2.5 mm long, calyx lobes 5, triangular-ovate, 2.5 × 3 mm, apex obtuse; corollas in bud to 10 mm long; corolla at anthesis white, fragrant, corolla tube 7-8 × 3 mm, corolla lobes 5, contorted to the right, 9-10 × 2-2.5 mm; ovary and nectary not seen. Infructescence with peduncle c. 11.5 cm long. Fruits apocarpous, composed of 2 fleshy mericarps, when fresh orange at maturity, ovoid-ellipsoid, 61-78 × 32-44 × 30-40 mm, mesocarp c. 7 mm thick; endocarp 54-72 × 27-40 × 23-34 mm, fibrous without, woody within, single-seeded. Seed 2 per fruit, ellipsoid, 29-37 × 18-19 × 3-4 mm.

Distribution.

Marquesas Islands, Fatu Hiva where originally known only from the type collected in Ouia Valley at 800 m.

Ecology.

This species was recently rediscovered in 2009 by Jean-François Butaud and Ravahere Taputuarai following the directions of Joseph Mititai. This population in Hanativa valley, a remote hanging valley north of Ouia, consists of 13 adult plants and numerous juveniles and seedlings at 480 m elevation. It occurs in mesic to wet forest with species of Aleurites , Allophylus , Artocarpus , Boehmeria , Cerbera , Inocarpus , Macropiper , Metrosideros , Musa troglodytarum L., Pandanus, Phyllanthus, Pipturus argenteus (G. Forst.) Wedd., Wikstroemia , the introduced Coffea arabica L. and Dioscorea spp.,and the ferns Nephrolepis biserrata (Sw.) Schott, Pteris comans G. Forst., and Tectaria jardinii (Mett. ex Kuhn) E. D. Br.

Conservation status.

Ochrosia fatuhivensis is currently known only from a single population. When evaluated using the IUCN criteria for endangerment it falls into the Critically Endangered (CR) category, which designates species facing the highest risk of extinction in the wild. IUCN Red List Category: Critically Endangered (CR) B1a, b; B2a, B2b ( i–iii): B1, extent of occurrence estimated to be less than 100 km2, and B1a, known to exist at only a single location; B1b (i-iii), continuing projected decline in (i) extent of occurrence, (ii) area of occupancy and (iii), area, extent and quality of habitat; B2, area of occupancy estimated to be less than 10 km2, and B2a, a single population known. B2b ( i–iii), habitat continuing decline inferred. The suitable habitat for Ochrosia fatuhivensis on Fatu Hiva (c. 85 km2) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals, and invasive plants, reducing the extent of the forest.

Specimen examined.

Marquesas Islands: Fatu Hiva: Hanativa, Affluent Sud de la vallée, vallon perché, 481 m, 7 Novembre 2009, Butaud, Taputuarai & Mititai 2458 (PAP).

Discussion.

Fosberg & Sachet (1972) suggested Ochrosia fatuhivensis may be related to Ochrosia compta K. Schum. of Hawaii, but no molecular-phylogenetic studies have been carried out involving these two species. The local name is ho’ei in Fatu Hiva, similar to the name holei used for species of Ochrosia in Hawaii ( Wagner et al. 1990). On Fatu Hiva the seeds were eaten in time of famine according to Brown (1935) and several present day inhabitants.