Elephantomene eburnea Barneby & Krukoff, 1974

Sousa, Julio Dos Santos De & Gurgel, Ely Simone Cajueiro, 2023, Emended description of the South American genus Elephantomene (Menispermaceae), Phytotaxa 579 (1), pp. 32-38 : 33-36

Elephantomene eburnea Barneby & Krukoff , Lloydia 37(1): 28–29, 1974.

Type:— FRENCH GUIANA. Saint-Laurentdu-Maroni: Maripasoula , Sa ̧l, Sur la route Boeuf Mort, 27 May 1971, fr., B. Oldeman 3925 (holotype CAY –64902; holotype fragment NY–320580!; isotypes: NY 320579!, P–00744924!; P–00744925!) Fig. 1 (A-P)

Cionomene javariensis Krukoff, Phytologia 41: 241, 1979. Type:— BRASIL. Amazonas, rio Curuçá , 8 miles above mouth, forest on terra firme, 26 October 1976, fl., G.T. Pranceet al. 24137 (holotype INPA–63582!; isotypes: MG–052507!; NY–320516!, NY–320517!, R –165292!, P–744896!, U–4404!, U–4405!, U–4406!, US –104022 4405!) .

Liana, 6–35 cm diam.; rhytidome ivory, fissured, tomentose; sapwood yellowish, not lenticillate. Petiole 5.1–13.9 × 0.3–0.5 cm, semi-cylindrical, fissured, tomentose. Leaf blade 12–20.2 × 10.9–22 cm, subcordiform, suborbicular or oval, coriaceous, bullate, adaxial surface glabrous, abaxial surface tomentose or velutinous; apex obtuse, subemarginate or mucronate; base emarginated to cordate; margin entire, ondulate, glabrous. Venation suprabasal actinodromous, primary veins 5-plinerved, impressed on adaxial surface; secondary veins 4–6, diverging from the lower third of the blade; tertiary veins scalariform, impressed. Staminate inflorescences in panicles, multiflorous, axillary or supraaxillary. Staminate flowers with green-cinereous perianth; sepals 1.5–6 × 1.5–4.5 mm; external sepals deltoid or oblanceolate, internal sepals oblanceolate, velutinous; petals 0.5–1.5 × 0.5–1 mm, submembranous, flabeliform, obdeltoid or obovate, velutinous, fixed on a column; stamens free, clavate, fixed on a column, anthers longitudinally dehiscent. Pistillate inflorescences in simple racemes, pauciflorous, supra-axillary. Pistillate flowers with greencinereous perianth (figure 2D–I); sepals 2–5 × 2.5–4.5 mm, deltoid or ovate, adaxially velutinous; petals 1–2 × 0.5–1.5 mm, submembranous, spatulate, velutinous in the margins and in the dorsal region; staminodes 6, 1.7–2 mm long, filiform, glabrous; ovary 2–3 mm long, sessile, ovoid, velutinous; stigma lobulated or flabelliform. Drupes 1.7–5.6 × 1.3–3.1 cm, ellipsoid or oblongoid, stipitate, orangish, striate, verrucous, velutinous or tomentose; apex obtuse to rounded, base cuneate, obtuse or asymmetrical; gynophores 1.2–2 mm long, tripartite, velutinous.

Examined specimens:— BRAZIL. Amazonas: Manaus, distrito agropecuário da SUFRAMA, rodovia BR-174, Km 64, próximo ao igarapé do acampamento Colosso , floresta de terra firme, 23 May 1991, fl. & fr., E. Setz 1020 (INPA); rio Curuçá , 8 miles above mouth, forest on terra firme, 26 October 1976, fl., G.T. Prance et al. 24137 (INPA, NY). ECUADOR. Napo: Tena, Estación Biológica Jatun Sacha, bosque muy húmedo tropical, 04 July 1996, fr., R. Ortiz & J. Vargas 205 (NY, MO); Costado sur del Rio Napo, bosque muy húmedo tropical, 04 August 1985, fr., D. Neill 6543 (NY). FRENCH GUIANA. Saint-Laurent-du-Maroni: Maripasoula, Sa ̧l, Sur la route Boeuf Mort , 27 May 1971, fr., B. Oldeman 3925 (NY, U); Sa̧l: Bélizon, 04 August 1993, fl., S.A. Mori 23108 (NY, MO); Sa̧l: La Fumée Mountain Trail, Antenne Nord, 27 July 1987, fr., S.A. Mori et al. 18586 (NY); Saint-Laurent-du-Maroni: vicinity of Les Eaux Claires, Route Bélizon, 22 September 2000, fl., N.P. Smith et al. 19 (U). PERU. Loreto: Requena, Distrito Sapuena, Centro de Investigación Jenaro Herrera , 12 June 2002, fl. & fr., R. Ortiz 237 (INPA, MO, U); Pasco: Oxapampa , Distrito Palcazú , Parque Nacional Yanachaga Chemillén , alrededores dela Estación Paujil , 06 September 2016, R. Vásquez et al. 40972 (MO).

Distribution: The species is distributed in French Guiana, Ecuador, Peru and Brazil, where its occurrence has been recorded only in the state of Amazonas ( Barneby 1993, BFG 2015, CRIA 2022, Tropicos 2022). Elephantomene eburnea was found only in terra firme forest, as pointed out by Barneby (2002). Flowering of the species usually occurs in the months of May, June, August and October, while fruiting was recorded in the month of May, July and August.

Elephantomene eburnea has insufficient data to accurately assess its conservation status.

Floral formala:

Staminate flower (♁): K3+ (3) C6 A6. Pistillate flower (♀): K3+3 C6 A º 6 G3. K: sepals. C: petals. A: stamens. G: carpels. A º: staminodes. Fig. 3 (A-B)

Figures

FIGURE 1. Elephantomene eburnea Barneby & Krukoff. A. Branch with pistillate inflorescences. B. External whorl of the staminate flower. C. Internal whorl of the staminate flower, showing the sepals, petals and stamens fixed on a column. D. Outer sepal. E. Petal surrounding the stamen. F. Petal. G. Stamen. H. External whorl of the pistillate flower. I. Internal whorl of the pistillate flower, showing the sepals, petals, gynoecium and staminodes. J. Petals, gynoecium, staminodes and stigma. K. Petal and staminode. L. Carpel. M. Detail of an infructescence with a drupe or attached to one of the three gynophores. N. External structure of the endocarp. O. Internal structure of the endocarp in the shape of an inverted “U”. P. Endosperm ruminate. A, H–L Ortíz 237 (INPA, MO), B–G Prance et al. 24137 (NY) and M–P Ortíz 237 (INPA, MO). Drawing by Carlo Alvarez and Julio Sousa.

FIGURE 3. Floral diagram of Elephantomene eburnea Barneby & Krukoff. A. Staminate flower. B. Pistillate flower.