8. Rhodostemonodaphne dioica

Rhodostemonodaphne dioica (Mez) Rohwer

Mitt. Inst. Allg. Bot. Hamb. 20: 83. 1986. Nectandra dioica Mez, Repert. Spec. Nov. Regni Veg. 16: 308. 1920. Type. Brazil. Acre: Rio Acre, São Francisco, Aug 1911 (stam. fl), Ule 9402 (holotype, B [photo F neg. 3753]; isotypes, G, K, US n.v [photo NY neg. 7037]).

Nectandra superba A. C. Smith, Phytologia 1: 120. 1935. Type. Brazil: Acre, Basin of Rio Purus, near mouth of Rio Macuahuan, 3 Sep 1933 (pist. fl), Krukoff 5757 (holotype, NY [photo NY neg. 7022]; isotypes, AA, B [xX2] [photo NY neg. 7716], BM, F [photo F neg. 405098], G, HBG [frag.], K, M, S, U, US).

Description

Trees: branches basitonic, in axils of cataphylls or basal foliage leaves; twigs angular and remaining so for at least two flushes, ca. 5 mm diam.; epidermis black, barely visible due to indument cover; terminal bud slender, ca. 1 X 1 mm; cataphylls caducous; indument pubescent to tomentose, caducous after one flush, the hairs dense, up to 1 mm long, crisped, erect, yellowish. Leaves: petioles robust, 1.5–2.7 cm X 2–3.5 mm, adaxially flattened; blades chartaceous, flat, broadly elliptic (ovate), 8–18 X 3–8 cm; base obtuse, minutely decurrent, 60–110°; apex acute, 60–100°, ultimately acuminate for up to 0.5(–1) cm; margin flatmargin plane; primary vein above flat, below raised; secondary veins 5–7 pairs, equidistant, eucamptodromous, above flat, below slightly raised, diverging at 50–55°, evenly arching (forked), chordal angle 20–30°, angle, the angle uniform along blade length; tertiary veins flat above, raised below, random-reticulate to scalariform; higher order veins above and below slightly raised; surface above dull to shiny, yellowish-green to yellowish-brown, below light yellowish-brown to creamy white; indument above glabrousabsent, primary , the primary vein tomentose, below tomentose, the hairs dense, up to 0.5 mm long, straight, appressed, ascending, yellowish, as well as up to 1.5 mm long, curved to crisped, erect and yellowish, persisting for at least two flushes. Staminate inflorescences: along whole length of flush, erect, peduncles 5–12 cm long, hypopodiathe hypopodia 2–5 cm X 1–2.4 mm, branch orders 6, second-order , the second-order branches 6–10, clustered apically, lowest branch up to 1.2(–3.5) cm long, color and indument of all axes as on twigs; bracts and bracteoles caducous (not seen). Staminate flowers: pedicels ca. 2.4 X 1 mm, the diameter even throughout; receptacle obconical, ca. 1.2 X 2 mm; tepals coriaceous, ovate, ca. 2.5 X 2.5 mm (inner whorl slightly smaller), at anthesis spreading to recurved, reddish, adaxially tomentose; stamens of whorls I and II minutely spathulate, anther , the anthersbroadly elliptical retuse, ca. 1 X 1.2 mm, with a few hairs at base, locelli, the locelli 4, apical, in a shallow arch, introrse, glands, the glands absent; whorl III columnar, ca. 1.2 X 0.8 mm, with a few hairs at base, locelli, the locelli 4, upperthe upper pair latrorse, lowerthe lower pair extrorse, glands, the glands globular, ca. 0.5 mm diam.; whorl IV absent; all stamens reddish; pistillode filiform, ca. 0.6 X 0.2 mm, glabrous. Pistillate flowers: pistil ca. 2.2 X 1.5 mm; ovary ovoid, ca. 1.2 mm long, glabrous. Fruits unknown.

Field notes

Trees up to 40 m tall and 61 cm diam.; buttresses very slender and steep; outer bark smooth, grey-brown with patches of grey; inner bark ca. 7 mm thick, cream, flecked red-brown; wood cream, red purple heartwood, wood non-aromatic. Pedicels yellow to reddish; tepals yellow.

Distribution

Found in the states of Acre (Brazil) and Pando (Bolivia), near the Brazil-Bolivia-Peru border, at 100–250 m elev., in rain forest.  Flowers August–September, at the beginning of the rainy season.

Additional specimens examined

Bolivia. Pando: Puerto Oro, 74 km SW of Cobija, 14 Aug [1988?] (stam. fl), Rh.R. T. Pennington et al. 123 (K, MO).

Discussion

Rhodostemonodaphne dioica is a very distinctive species.  Its mixed indument on the underside of the leaves, consisting of both appressed-ascending and erect hairs is unique in the genus.  It has relatively large flowers intermediate in size between those of Rh.R. saülensis and Rh.R. anomala.

Nectandra dioica was incorrectly synonymized with N. grandis by Kostermans (see discussion of Rh.R. grandis).  Rohwer (1986) reinstated it, adding N. superba as a synonym.
Contact | Updated 28.07.2005 | ©2005 Santiago Madriñán