19. Guatteria ayangannae Scharf & Maas — Map 7 Guatteria ayangannae Scharf & Maas in Scharf et al. (2005) 565,f. 2. — Type: Clarke et al. 9819 (holo U 2 sheets; iso BRG, NY 4 sheets), Guyana, Potaro-Siparuni Region, Upper Potaro River, near camp, Mt Ayanganna, 650 m, 3 July 2001. Tree 5–7 m tall, c. 10 cm diam; young twigs densely covered with erect, orange-brown hairs to c. 1.5 mm long, soon glabrous. Leaves: petiole 7–14 mm long, 1–2 mm diam; lamina elliptic to obovate, 10–17 by 4–6 cm (leaf index 2.1–2.9), coriaceous, scabridulous particularly below, pale to creamy brown above, brown below, glabrous above, densely covered with appressed, orange-brown to silvery hairs to c. 1.5 mm long below when young, soon becoming sparsely covered with appressed hairs to c. 0.5 mm long, then becoming glabrous, base acute, apex acuminate (acumen 5–10 mm long), primary vein impressed above, secondary veins distinct, 9–14 on either side of primary vein, flat above, smallest distance between loops and margin 2–4 mm, tertiary veins flat above,reticulate. Flowers in 1–2-flowered inflorescences in axils of leaves; pedicels 5–15 mm long, c. 2 mm diam, fruiting pedicels to c. 15 mm long, c. 3 mm diam, densely covered with appressed, orange-brown hairs, articulated at 0.3–0.5 from the base, bracts 5–6, the lower bracts soon falling, elliptic-ovate, c. 2 mm long, the 2 upper ones often persisting till flowering time, often foliaceous, elliptic to narrowly elliptic, 7–40 mm long, to 15 mm wide; flower buds broadly ovoid, slightly pointed; sepals basally connate, triangular, 9–10 by 5 –6 mm, often reflexed, apex strongly acuminate, outer side densely covered with appressed, orange-brown hairs; petals greenish yellow or yellow in vivo, elliptic to ovate, 14–18 by 6 –10 mm, outer side densely covered with appressed, orange-brown hairs; stamens c. 2 mm long, connective shield hairy. Monocarps 2–8, green to reddish brown in vivo, black in sicco, narrowly ellipsoid, 15–23 by 4–6 mm, sparsely covered with appressed hairs to c. 0.5 mm long to glabrous, apex nipple-shaped (nipple c. 2 mm long), wall 0.3–0.5 mm thick, stipes 5–8 by 1–2 mm. Seed narrowly ellipsoid, 13–15 by 4–5 mm, dark, shiny brown, smooth to slightly pitted, raphe not distinct from rest of seed. Distribution — Guyana (Mt Ayanganna). Habitat & Ecology — In dense, mixed evergreen forest with Dicymbe, Pentaclethra, Clusia, Socratea and Euterpe, on grey, alluvial sand, sandstone, peat, or lateritic soil. At elevations of 650–1120 m. Flowering: June to August; fruiting: June to August. Vernacular names — Not recorded. Note — Guatteria ayangannae is only known from Mt Ayanganna in Guyana. It is a very beautiful species, particularly by its young vegetative and floral parts which are densely covered with appressed, orange-brown hairs up to c. 1.5 mm long. The acuminate, basally fused sepals and the presence of foliaceous bracts are other features by which this species is easily recognized.

Published as part of 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), pp. 1-219 in Blumea 60 (1) on pages 41-43, DOI: 10.3767/000651915X690341, http://zenodo.org/record/16855128