Coprosma esulcata (F. Br.) Fosberg, Brittonia 8: 178. 1956.

Wagner, Warren L. & Lorence, David H., 2011, Revision of Coprosma (Rubiaceae, tribe Anthospermeae) in the Marquesas Islands, PhytoKeys 4, pp. 109-124 : 112-113

Coprosma esulcata (F. Br.) Fosberg, Brittonia 8: 178. 1956.

Psychotria esulcata F. Br. (Bernice P. Bishop Museum Bulletin 130: 315. 1935). [Basionym]

Type.

Marquesas Islands: Ua Pou: Without further locality, 1000 m, 1921, E. Qualye 1136(holotype: BISH-578803!).

Description.

Shrub or small tree 1.5-4 m tall; young stems glabrous. Leaves decussate, thick-coriaceous, blades 6.5-13 × 2.7-6 cm, ellipticoblanceolate, pinnately veined with 8-18 pairs of secondary veins, higher level venation conspicuously reticulate, upper surface glabrous, lower surface strigose along the veins, midrib broad, with a narrow wing, domatia small or sometimes apparently absent, located along midrib near juncture of secondary veins, apex acuminate, base cuneate; petioles 0.4-1.3 cm long, stout, narrowly winged; stipules ca. 3-8 mm long, connate 1/2-4/5 of length, both surfaces glabrous, margins ciliate with reddish brown hairs and dentate with conspicuous colleters, apex obtuse to a conspicuous appendage. Inflorescences axillary with 6(-15) flowers, trichotomously branched, with 1-3 nodes, the uppermost with a 3-flowered cymule, the others with usually only 1-2 flowers developing on each, these 5-6-merous, peduncles finely, sparsely strigulose. Flowers: male flowers with calyx campanulate, ca. 2 mm long, the tube 1 mm long, the lobes 1 mm long, corolla 6-7 mm long, the tube 5 mm long, the lobes ca. 2 mm long, staminal filaments 7 mm long; female flowers with peduncles 2-3 mm long, calyx tubular, 0.4-0.8 mm long, corolla narrowly funnelform, the tube 1.8-2 mm long, the lobes 1.4-1.8 mm long, the styles 9-11 mm long. Fruits ca. 6-7 mm long × 3 mm wide, obovoid-elliptic, ripening bright red or reddish orange, apex with persistent calyx teeth. Pyrenes obovoid-ellipsoid, ca 4 mm long × 2.5-3 mm wide hemispherical in cross-section, smooth, heavily slerified on the edges and on the flat inner face, thin on convex side.

Distribution.

Marquesas Islands, scattered to locally common on Ua Pou and a single collection known from Nuku Hiva.

Ecology.

This species is known from 770 to 920 m elevations on steep slopes or ridges in cloud-shrouded shrubland and wet forest dominated by Freycinetia impavida (Gaudich. ex Hombr.) B. C. Stone, Pandanus tectorius Parkinson, and Metrosideros collina (J. R. Forst. & G. Forst.) A. Gray.

Specimens Examined.

Marquesas Islands: Nuku Hiva. between Taiohae Bay and Hooumi Bay, 900 m, Gagné 1159 (BISH, US). Ua Pou: Teavaituhai, 3000 ft, Mumford & Adamson 642 (BISH), Meyer 2835(PTBG, US); Teavahaakiti, steep slopes of main ridge to S of Oave, N & E facing cliffs between Teavahaakiti & Tekohepu, 2700 ft, Perlman & Wood 15905 (PTBG), 2550 ft, Perlman & Wood 15922 (PTBG, WU); Matahenua, between Oave and Poutetainui, high mountain peaks along main backbone ridge, 899 m, Perlman & Wood 19079(P, PAP, PTBG, US); forested ridge and slopes up to Teavahaakiti, northwest side, 914 m, Wood 10440 (PAP, PTBG, US), Wood 10446 (PTBG, US); central Ua Pou including the summit crest regions around Oave and the near-by peak of Matahenua., 2950-3030 ft, [09°23'454"S, 140°04'433"W], Wood & Perlman 10802 (PAP, PTBG, US); Tekohepo, summit, 2500-3000 ft, [09°24'31"S, 140°04'21"W], Wood & Perlman 6487 (PAP, PTBG), Wood & Perlman 6492 (PTBG).

Conservation status.

Following the criteria and categories of IUCN (2001) it is assigned a preliminary status of Endangered (EN): B1, B2b ( i–iii): B1 extent of occurrence <5,000 km²; B2: total area of occupancy less than 500 km² (c. 50 km²); B2b ( i–iii), habitat continuing decline inferred in (i) extent of occurrence, (ii) areas of occupancy, and area, (iii) extent and/or quality of habitat. The suitable habitat for Coprosma esulcata on Nuku Hiva (c. 340 km²) and Ua Pou (c. 105 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.