Guatteria rostrata Erkens & 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 : 145

136. Guatteria rostrata Erkens & Maas — Fig. 66 ; Map 29

Guatteria rostrata Erkens & Maas in Erkens et al.(2006) 210,t. 2, f. 5. — Type: R. Aguilar et al. 3654 (holo U; iso CR, INB, MO), Costa Rica, Puntarenas, Cantón Osa, Reserva Forestal Golfo Dulce,near Rancho Quemado , 200– 350 m, 1 Nov. 1994.

Tree 7–20 m tall, 20–60 cm diam, black or grey; young twigs densely covered with appressed hairs, soon glabrous. Leaves: petiole 15–20 mm long, 2–3 mm diam; lamina elliptic to obovate or narrowly so, 18–28 by 7–11 cm (leaf index 2.4–2.6), chartaceous, not verruculose, dull, greyish brown above, brown below, glabrous above, rather densely covered with appressed hairs below, base attenuate into a narrowly winged petiole, apex acuminate (acumen 10–20 mm long), primary vein impressed above, secondary veins distinct, 16–19 on either side of primary vein, raised above, smallest distance between loops and margin 3–6 mm, tertiary veins raised above, reticulate. Flowers in 1–2-flowered inflorescences on leafless branchlets or in axils of leaves; pedicels 15–35 mm long, c. 1 mm diam, fruiting pedicels to c. 2 mm diam, densely covered with appressed hairs, finally glabrous, articulated at 0.2–0.3 from the base, bracts 5–7, soon falling, not seen; flower buds broadly ovoid; sepals free, broadly ovate-triangular to ovate-triangular, 7–12 by 5–10 mm, spreading, outer side rather densely covered with appressed hairs; petals green or yellowish green to yellow in vivo, unequal, outer ones ovate, 14–22 by 10–15 mm, inner ones oblong-elliptic to ovate, 10–15 by 5 –9 mm, outer side densely covered with appressed hairs; stamens c. 2 mm long, connective shield papillate. Monocarps 5 –15, green, maturing red to purple-black in vivo, black in sicco, narrowly ellipsoid, 15–18 by 6–7 mm, sparsely covered with erect hairs, soon glabrous, apex rostrate (beak 1–2 mm long), wall 0.1–0.2 mm thick, stipes 3–10 by c. 1 mm. Seed ellipsoid, 13–15 by 4–7 mm, pale brown, trans- versely grooved to pitted, raphe impressed.

Distribution — Costa Rica.

Habitat & Ecology — In forest. At elevations of 0– 700 m. Flowering: May, July; fruiting: February, May, June, November.

Vernacular names — Not recorded.

Field observations — Flowers with strong odour ( Raaijmakers & Rodríguez 87, Costa Rica).

Note — In the field G. rostrata is easily recognized by its black or grey trunk, sometimes with narrow buttresses reaching up to 8 m (Hammel 16960). In the field this species superficially resembles G. amplifolia somewhat because of its large leaves. In G. rostrata , however, the petiole is generally somewhat longer (15–20 by 2–3 mm vs 4–10 by 4–6 mm). Moreover, the monocarps of G. rostrata are 5–15 in number, 15–18 by 6–7 mm and rostrate, while G. amplifolia has more monocarps (20–40), which are shorter (8–10 by 5–6 mm) and ellipsoid to pyriform, lacking the rostrate apex.

Figures

Fig. 66 Guatteria rostrata Erkens & Maas. a. Branch with flower buds; b. fruit; c. flower (a, b: Maas et al. 9497; c: Maas et al. 9492). — Drawing by Hendrik Rypkema.