Coccoloba gigantifolia E. Melo, C.A. Cid Ferreira & R. Gribel. Acta Amazon.

Ancona, Juan José, Ortiz-Díaz, Juan Javier, Gutiérrez-Alonso, Eduardo & Ledesma, Patricia Hernández, 2025, A taxonomic revision of Coccoloba sect. Paniculatae (Polygonaceae, Eriogonoideae), Phytotaxa 704 (2), pp. 106-152 : 118-120

3. Coccoloba gigantifolia E. Melo, C.A. Cid Ferreira & R. Gribel. Acta Amazon. 49(4): 325. 2019. ( Figs. 6A–E ).

Type:— BRAZIL. Rondônia: Floresta Nacional do Jamari, Serra da Onça, 2 km from the residential village, 09º01’S, 63º02’W, 05 September 2008, Cid Ferreira et al. 11211 (holotype INPA! [photo]).

Description:—Trees polygamous-dioecious, 10‒15 m tall; branches, glabrous or sparsely pubescent to abundantly pubescent when young, greyish, lenticelated; ochrea 5–10 cm long, persistent at base, coriaceous, pubescent ferruginous, apex with acuminate edge, scariose and deciduous. Leaves simple, spiral; petiole 5–10 cm long, 1–2 cm diameter, smooth, older leaves are completely glabrous or puberulous, inserted at base of the ochrea; leaf blade elliptic, 0.6–2.5 m long, 0.5–1.4 m wide, coriaceous or subcoriaceous, discolor, pubescent-glabrescent, both surfaces with ferruginous trichomes, in the abaxial one, concentrated in the veins when young, apex acute or acuminate, base obtuse, subcordate, subtruncate, entire margin, undulate, brochidodromous venation, 16–45 pairs, abaxially prominent. Inflorescence spiciform, arranged in a large monopodial panicle, branches>20, main axis elongated, 40–80 cm long, 2.5 cm diameter, ribbed, pubescent or puberulent, glabrescent; spiciform portion 10–15 cm long, rachis ribbed, striate, 2.5 mm diameter, pubescent or puberulent, glabrescent; bracteole 0.2–0.5 mm long, triangular or cymbiform, coriaceous, puberulent or pubescent; ochreola 0.5–10 mm long, campanulate, membranaceous, puberulent or pubescent with bilobed edge, persistent and lacerated after fruit maturation; pedicels in flower 0.5 mm long, pedicels in fruit 0.5 mm long, thicker, hirsutulous to strigose, pulverulent. Flowers in two whorls, outer tepals 3, inner tepals 2, alternate; flowers functionally male solitary; hypanthium 0.7–1 mm long, campanulate, puberulent; outer tepals glabrous or puberulent, coriaceous, inner tepals glabrous, papyraceous; tepals 1.2–1.5 mm long; stamens 7–8, 1.5–2 mm long, filaments filiform 1–1.5 mm long, anthers 0.5 mm long; vestigial pistil; flowers functionally female solitary; hypanthium 0.7–1 mm long, campanulate, puberulent; outer tepals glabrous or puberulent, coriaceous, inner tepals glabrous, papyraceous; tepals 1.2–1.5 mm long; stamens 7–8, reduced, ovary ovoid, style 3, glabrous, stigmas capitate papillose. Fruit acrosarcum, 5–8 mm long, 5–7 mm diameter, globose, subglobose, pubescent or puberulent, red, vinaceous or purple when mature, apex acute to obtuse, base truncate or flat, not abruptly contracted at junction with pedicel; hypanthium accrescent, succulent, almost completely enclosing achene, tepals accrescent, glabrous, succulent, appressed at the apex tuberculate of the achene. Achene 5–8 mm long, 5–7 mm diameter, globose-subglobose, base truncate or flat, apex tuberculate, conical, prominent, brown, smooth, glossy.

Etymology: — The specific epithet C. gigantifolia refers to the extremely large leaves.

Phenology:—Cultivated trees in Manaus bloomed from March to June and exhibited mature fruits in September.

Distribution and ecology:— Coccoloba gigantifolia is endemic to the Madeira River basin. So far, individuals have been recorded in the states of Amazonas and Rondônia ( Fig. 6F ). Individuals have been collected in the wild only in the middle (Jamari and Samuel) and lower (Autazes and Borba) stretches of the Madeira River basin. Coccoloba gigantifolia grows in open, ombrophylous forests, secondary forests, and in early successional stages (capoeira, in Portuguese), in elevation of 20–100 m, in areas of flat relief, on sandy or clayey, humid soils.

Provisional conservation status:—Melo et al. (2019) suggested that the species be classified as “Endangered”, which includes taxa at high risk of extinction in the wild according to the IUCN criteria established in the Red Book of Flora of Brazil ( Martinelli & Moraes 2013), since it is very likely that the small and possibly disjunct wild populations of C. gigantifolia will be severely threatened in the near future by fires and deforestation caused by the advance of agriculture and road infrastructure.

Discussion: — Coccoloba gigantifolia is an exceptional case within the Polygonaceae , even within the dicotyledons, because its leaves reach dimensions of 0.6–2.5 m long, 0.5–1.4 m wide. Given the dimensions of the mature leaves 1.50–2.5 m ( Fig. 5 ), the available herbarium specimens only consist of inflorescences. It is also important to mention that all fertile materials deposited at INPA Herbarium from 2008 to present come from the individuals cultivated in Manaus, which originated from seeds of an individual of the Jamari River region. The leaves were dried and preserved in wooden frames protected with glass for public display at the INPA and other institutions.

The original morphological descriptions were based mainly on specimens grown in the INPA gardens plus photographs of the specimens in their natural habitat. Flowers and fruits were collected and fixed in liquid substances to preserve them and to obtain morphometric measurements. Given the absence of digitized herbarium specimens for this treatment, we used available photographs on the WEB (Creative Commons Licenses), plus the publication of the protologue, as well as the only digitized specimen in the CEN herbarium.

Currently, only four localities with living populations of Coccoloba gigantifolia , cited in the protologue, are known, they were used then, to make the distribution map of the species and are the same ones used in this contribution for the same purpose.

Specimens examined:— BRAZIL. Rondônia: Porto Velho, presa hidroeléctrica Jirau, BR-364, 09º15’S, 64º21’W, 28 Mar.2011, (fl.), MF Simon et al. 1237 (CEN).

Figures

FIGURE 5.A. Specimen of Coccoloba efigeniana (J. Marín 112, MO); B. Portion of inflorescence, bracteole and ochreola; C.Acrosarcum lateral view; D. Acrosarcum polar view; E. Achene lateral view; F.Achene polar view; G. Distribution model.

FIGURE 6. A. Photograph showing the leaf size of Coccoloba gigantifolia; B. Ochrea with puberulent indumentum; C. Inflorescence; D. Infructescence; E. Acrosarcum; F. Geographical distribution. Figures A–E taken from Melo et al. 2019 (Creative Commons Licenses).