Guatteria partangensis Scharf & Maas

Maas, P. J. M., Westra, L. Y. T., Guerrero, S. Arias, Lobão, A. Q., Scharf, U., Zamora, N. A. & Erkens, R. H. J., 2015, Confronting a morphological nightmare: revision of the Neotropical genus Guatteria (Annonaceae), Blumea 60 (1), pp. 1-219 : 130

120. Guatteria partangensis Scharf & Maas — Map 22

Guatteria partangensis Scharf & Maas in Scharf et al. (2005) 569, f. 4. — Type: Tillett et al. 43975 (holo K; iso BRG,MO,NY,S,US), Guyana, Merume Mts, Partang River, 3 July 1960.

Tree c. 8 m tall, diam not recorded; young twigs densely covered with erect, long-persisting hairs 1–1.5 mm long. Leaves: petiole 3–5 mm long, c. 2 mm diam; lamina narrowly elliptic, 8–15 by 4–5 cm (leaf index 2.8–3.2), coriaceous, not verruculose, dull, greyish brown above, dark to yellowish brown below, glabrous above, but primary vein covered with a dense row of hairs, soon glabrous, rather densely covered with erect hairs c. 1 mm long below, base obtuse, apex acuminate (acumen 10–25 mm long), primary vein impressed above, secondary veins distinct, 6 – 9 on either side of primary vein, raised above, smallest distance between loops and margin c. 1 mm, tertiary veins raised above, reticulate. Flowers solitary in axils of leaves or on leafless branchlets; pedicels c. 40 mm long, c. 1 mm diam, fruiting pedicels c. 50 mm long, 1–1.5 mm diam, densely cover- ed with erect hairs c. 1 mm long, articulated at 0.2–0.4 from the base, bracts 4–5, soon falling, not seen; flower buds not seen; sepals free, broadly ovate-triangular, 5–7 by 5–7 mm, appressed, outer side densely covered with erect hairs; pet- als pale green in vivo, elliptic, 20–25 by 7–11 mm, outer side densely to finally sparsely covered with erect, more or less curly hairs; stamens 1.5–2 mm long, connective shield papil- late, flat to umbonate. Monocarps 8–10, black in vivo, brown in sicco, ellipsoid, 8–11 by 7–8 mm, glabrous, apex apiculate (apiculum <0.5 mm long), wall c. 0.1 mm thick, stipes 17–20 by c. 1 mm. Seed ellipsoid, c. 10 by 6 mm, dark, shiny brown, pitted, raphe slightly raised.

Distribution — Guyana (Merume Mts).

Habitat & Ecology — In forest, along ridge trail of mountain. At an elevation of c. 500 m. Flowering: July; fruiting: July.

Vernacular names — Not recorded.

Note — Guatteria partangensis , only known from the type collection, slightly resembles G. ouregou , a species restricted to French Guiana, due to its erect, long hairs on young twigs and pedicels. It differs from the latter by a lower number of secondary veins (6–9 vs 11–15) and longer pedicels (40–50 vs 10–25 mm).