15. Guatteria argentea Erkens & Maas — Plate 2d; Map 5 Guatteria argentea Erkens & Maas in Erkens et al. (2008) 473, f. 2. — Type: Monsalve B. 1262 (holo U; iso CUVC, MO), Colombia, Valle del Cauca, Bajo Calima, Concesión Pulpapel/Buenaventura, 100 m, 13 Nov. 1986. Tree 6–12 m tall, diam not recorded; young twigs densely covered with appressed, silvery hairs, soon glabrous. Leaves: petiole 8–15 mm long, 2–3 mm diam; lamina obovate, rarely narrowly so, 9–12 by 3.5–6 cm (leaf index 2–2.5), coriaceous, densely verruculose, slightly shiny, dark brown to greyish black above, brown below, glabrous above, densely covered with appressed, silvery hairs below, base attenuate, apex shortly acuminate (acumen 1–5 mm long), primary vein impressed above, keeled below, secondary veins distinct, 9–13 on either side of primary vein, raised to flat above, smallest distance between loops and margin 3–4 mm, tertiary veins slightly raised to flat above, reticulate. Flowers solitary in axils of leaves; pedicels 5 – 9 mm long, 1–2 mm diam, fruiting pedicels 10–15 mm long, c. 2 mm diam, densely to rather densely covered with appressed, silvery hairs, articulated at 0.3–0.5 from the base, bracts 3–4, soon falling, the upper one c. 4 by 3 mm; flower buds depressed ovoid to ovoid; sepals free, broadly ovate-triangular, 3–5 by 4–6 mm, appressed, outer side densely covered with appressed, silvery hairs; petals yellowish green in vivo, elliptic to obovate, 9–13 by 5–8 mm, outer side densely covered with appressed, silvery hairs; stamens 1–1.5 mm long, connective shield hairy. Monocarps 10–15, green to yellow in vivo, brown to blackish in sicco, ellipsoid, 12–16 by 5–8 mm, sparsely covered with appressed hairs, apex apiculate (apiculum <0.5 mm long), wall 1–1.5 mm thick, stipes 2–6 by c. 2 mm. Seed ellipsoid, 10–12 by c. 5 mm, shiny, dark brown, pitted, raphe not distinct from rest of seed. Distribution — Colombia (Antioquia, Valle del Cauca). Habitat & Ecology — In forest (‘bosque pluvial tropical’). At elevations of 50– 200 m. Flowering: February, August, October to December; fruiting: February,August, November, December. Vernacular names — Not recorded. Notes — Guatteria argentea is very easily recognizable by its silvery indument on many parts of the plant and by its obovate, densely verruculose leaves with an attenuate base. The type of the present species (Monsalve B.1262) has been used by Erkens et al. (2007a, b) for a phylogenetic study on Guatteria. However, in these studies this specimen was assigned to G. heterotricha R.E.Fr. It was placed sister to G. rotundata to which it looks quite similar. Guatteria rotundata is from Panama (Panamá and San Blas) and the two species share the obovate leaves. Guatteria argentea differs by its dense silvery indument of the young twigs and lower side of the lamina and by its more densely verruculose leaves.

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 page 37, DOI: 10.3767/000651915X690341, http://zenodo.org/record/16855128