Duguetia argentea (R.E.Fr.) R.E.Fr.

  • Authority

    Maas, Paulus J. M., et al. 2003. (Annonaceae). Fl. Neotrop. Monogr. 88: 1-274 pp. (Published by NYBG Press)

  • Family

    Annonaceae

  • Scientific Name

    Duguetia argentea (R.E.Fr.) R.E.Fr.

  • Type

    Type: Venezuela. Amazonas: San Carlos de Río Negro, Oct 1854 (fl, fr), Spruce 3814 (lectotype, B, designated by Fries (1934), only photograph seen; isolectotypes, B, BM, C, E, F, G, GH, GOET, K, LE, MG, NY, OXF, P, TCD).

  • Synonyms

    Duguetia amazonica R.E.Fr.

  • Description

    Species Description - Tree or shrub, 3-8 m tall (to 20 m in García-Barriga 14366), to 30 cm in diam. Young twigs and petioles totally covered with brownish, stellate (the smaller ones) to subentire (the larger ones) scales 0.1-0.5 mm in diam. Petioles 3-7 mm long, 1-2 mm in diam. Lamina narrowly elliptic to narrowly ovate, 7-20 cm long, 1.5-5 (-6) cm wide, leaf index 3-5, chartaceous, brownish, blackish green, or greyish green above, grey or greyish green to pale brown below, glabrous above, rather densely to totally covered with pale brown, stellate (the smaller ones) to subentire scales (the larger ones) 0.1-0.5 mm in diam. below, base acute to obtuse, apex acuminate (acumen to 30 mm long) to acute, primary vein impressed above, secondary veins straight, 11-20 on either side of primary vein, flat to slightly raised above, angles with primary vein 80-90°, loop-forming at obtuse angles, loops distinct, smallest distance between loops and margin 1.5-3 mm, tertiary veins flat above. Inflorescences among leaves, terminal, sub-axillary, or leaf-opposed, a single rhipidium or rarely composed of 2 rhipidia. Rhipidia 1-2-flow-ered, occasionally few flowers in succession. Indument: peduncles, pedicels, and outer side of bracts, sepals, and petals totally to densely covered with stellate scales 0.2-0.7 mm in diam, inner side of sepals and outer petals totally covered with white, stellate hairs to 0.5 mm in diam, inner side of inner petals totally covered with white, stellate scales to 0.5 mm in diam. Peduncle 1-2 mm long, 1 mm in diam., fruiting peduncle to 4 mm long, and to 2 mm in diam. Sympodial rachis, if developed, to 3 mm long. Pedicels 3-6 mm long, 1 mm in diam., fruiting pedicels to 10 mm long, 2-3 mm in diam. Upper bract halfway the pedicel, or less often at 1/4 or 3/4, depressed ovate, 1-2 mm long, caducous. Flower buds depressed ovoid. Flowers green when young, maturing yellow to creamy white in vivo, inner base of inner petals reddish tinged. Sepals free, ovate-triangular, 15-25 mm long, 9-20 mm wide, acute. Petals unequal, the outer ones ovate, with one prominent rib (in one specimen), 20-35 mm long, 10-18 mm wide, acute, top angle to almost 90°, the inner ones ovate-spathulate to narrowly ovate-spathulate, 20-35 mm long, 8-13 mm wide, acute, base concave, callose, strongly grooved. Stamens ca. 3 mm long, cream, apex of connective discoid, 0.4 x 1.2 mm, densely covered with simple hairs. Carpels 2-5 mm long, ovary totally covered with stellate scales, stigma subglabrous. Fruit green to very pale yellow in vivo, subglobose to broadly ovoid, 2-3 cm long and 2-3 cm in diam., sepals often persistent, basal collar absent, fertile carpels (25-)35-60, obtrulloid to obovoid, 8-10 mm long, 6-7 mm in diam., free, areoles very shallowly pyramidal, 1-3 mm high, obtuse, apiculate (apicule slightly curved upwards, 1-2 mm long), smooth, totally covered with greyish white, stellate scales ca. 0.2 mm in diam. Seeds ellipsoid, 8-10 mm long, 4-5 mm in diam., acute, slightly apiculate, pale brown to orange-brown, shiny.

  • Discussion

    Duguetia argentea is restricted to periodically inundated forests of the Amazon Region. It is well marked by rather narrow leaves, a rather dense to very dense indument of stellate to subentire scales on the lower side of the leaves in combination with a rather small fruit (2-3 cm in diam). At first view D. argentea is closest to D. dimorphopetala, D. oblongifolia, and D. venezuelana. UPGMA analysis places these three species in one cluster, but D. argentea is combined with this cluster only at the lower level. For further particulars, see chapter on Internal Relationships, and Fig. 37 (5th cluster). An overview of the four species is given in Table X.

    There is no reason to maintain D. argentea and D. amazonica as separate species, as both gradually merge into each other. This applies equally to leaf, indument, and flower characters formerly used by Fries (1934).

  • Common Names

    Sasirana, Envira, Sasirano, Numayukirika, majagua, Majagua anon de hoja fina, Majagua rebalsera

  • Distribution

    Amazonian Colombia, Venezuela, and Brazil. In periodically inundated forest (igapó, rebalse, várzea), one collection from non-inundated forest, and one from “campinarana alta.” At elevations up to 250 m. Flowering and fruiting throughout the year.

    Colombia South America| Amazonas Colombia South America| Vaupés Colombia South America| Guainía Colombia South America| Venezuela South America| Amazonas Venezuela South America| Brazil South America| Amazonas Brazil South America| Pará Brazil South America|