Pelliciera rhizophorae Planch. & Triana

Duke, N. C., 2020, A systematic revision of the vulnerable mangrove genus Pelliciera (Tetrameristaceae) in equatorial America, Blumea 65 (2), pp. 107-120 : 113

2. Pelliciera rhizophorae Planch. & Triana — Fig. 1 , 4 ; Map 1

Pelliciera rhizophorae Planch.& Triana ( ‘ Pelliceria ’) in Triana & Planch.(1862) 381, p.p.; Hemsl. (1879) 97, t. 8, p.p.; Kobuski (1951) 256, p.p.; Toml. (1974) 293; Von Prahl (1987) 118, p.p.; Castillo-Cárdenas et al. (2015b) 503, t. 2, ‘Variant A’. — Type: Triana & Planchon s.n. (holo P!; iso COL 16552),Columbia,Pacific coast,Dept.del Valle,Port of Buenaventura Bay.

Etymology. The epithet ‘ rhizophorae ’ refers to similarities in root structures with the family Rhizophoraceae .

Trees, to 12(–18) m high. Foliage comprised of 7–10 leaves, apical shoots 8.5–11.8 cm long. Leaves 11.7–12.7 by 3.5–3.7 cm, 3.3–3.5 times longer than wide, widest 6.3–6.7 cm from base, wide-side 2–2.1 cm wide, margins entire on narrow side, dentate with glands on the wider margin, 12 –15 per 20 mm in central part of blade, often shed with age, distance of furthest gland from leaf base 0.8–1 cm ( Fig. 1 ). Bract 10.4–12.7 by 3.1–3.8 cm, 3–3.4 times longer than wide, widest 1.8–3 cm from base, narrow-side dentition absent, wide-side dentition present, length of non-dentate portion 1.7–1.9 cm, teeth c. 14 per 2 cm ( Fig. 1 ); bracteoles foliaceous, 8.7–8.9 by 3.6–4.5 cm, 2–2.5 times longer than wide, widest 3.6–4.2 cm from base, narrow-side and wide-side dentition absent, whitish green. Flowers: sepals 2–2.4 by 1.6–1.9 cm, 1.1–1.4 times longer than wide, glands 196–400, gland-free margin at apex 5.3–7.3 mm wide, gland-free margin at sides 2.8–4.3 mm long ( Fig. 1 ); petals oblong to lanceolate, 6.9–7.3 by 1.2–1.4 cm, 4.9–6.1 times longer than wide, widest 1.2–1.7 cm from base, white mostly, rarely tinged pink with a white midvein; anthers 2.5–3.9 cm long; pistil 6.7–7.3 cm long, ovary 3–4.1 cm by 4.7–6.6 mm; style 2.8–3.8 cm by 2.4–2.8 mm, surface percentage ribbed vs smooth 44–59 %. Fruits 10.5–12.3 by 7.2–8.5 by 4.3–4.7 cm, c. 1.5 times longer than wide, thick, less than 2 cm in width; wall 6.9–7 mm thick at base. Paired cotyledons 7.7–8.3 by 6.6–7.4 by c. 2.9 cm, 1–1.3 times longer than wide, individually 1.5–1.7 cm thick, plumule base 1–1.1 cm wide, stem base 0.6–0.7 cm wide.

Distribution — Pelliciera rhizophorae has a limited distribution (c. 48 populations) in the Atlantic-East Pacific region, mostly on the Pacific coast of the Central American Isthmus and northern South America ( Costa Rica, Panama, Colombia to Ecuador), but with notable occurrences also on the Atlantic coast ( Honduras, Nicaragua to Panama and possibly to Uraba Gulf in Colombia (Blanco-Libreros pers. comm.; Appendix 1, Map 1). The genus has a broad relict fossil range extending from Mexico and throughout the Caribbean region across northern South America to Brazil, to Nigeria and Europe across the north Atlantic.

Habitat & Ecology — Pelliciera rhizophorae occurs often as closed canopy stands at low to mid-intertidal positions of downstream to intermediate estuarine locations within larger freshwater dominated estuaries. Plants are evergreen with leaf emergence and leaf fall occurring all year round. Flowering: April to June; fruiting: November to December ( Duke & Pinzón 1993a –b). Flowers were visited by various nectar eating birds, moths, bats and hummingbirds. Hummingbirds gathered nectar by trapline foraging. The sugar content of sepal nectaries was around 14.1 % w/w fructose, 15.8 % w/w glucose and 13.7 % w/w sucrose. In addition, there were extra-floral nectaries at the base of each leaf. All these nectaries were used by ants and other insects ( Collins et al. 1971), as well as by hummingbirds ( Von Prahl 1987, Gutiérrez et al. 1989, Von Prahl et al. 1990).

Conservation status — Populations of P. rhizophorae are often distant from each other, and propagules are partially buoyant and appear to be dispersed by water ( Rabinowitz 1978a –b). Genetic evidence indicates there has been minimal gene flow between populations ( Castillo-Cárdenas et al. 2015a –b). The total area of P. rhizophorae populations is estimated to be less than 500 km 2. The quality of habitat for this uncommon species is declining throughout its range (e.g., Blanco-Libreros et al. 2015), primarily due to coastal development. The IUCN Red List status for P. rhizophorae needs to be revised from Vulnerable under criterion B (see http://www.iucnredlist.org/) to a higher threatened level, in consideration of this revision.

Additional specimens examined. COLOMBIA, Pacific coast, Dept.del Choco , trocha de Utria al Valle, June 1950, Fernandez 263 ( COL 34074 ) ; Pacific coast, Dept. del Valle, Buenaventura Bay , mangrove, May 1922, Killip 5222 ( AA, NY, US) ; Pacific coast, Dept. de Narino, Tumaco , June 1955, Romero­ Castaneda 5298 ( COL 65857 , 65858 ) . – COSTA RICA, Pacific coast, Punta Mala , Mar. 1892, Tonduz 6723 (US) . – ECUADOR, Prov. Esmeraldas, Borbon on Rio Santiago , May 1943, Little 6423 (US) . – HONDURAS, Atlantic coast, Gracias a Dios, Barra de Karataska , June 2014, Helder Perez 129217 ( EAP) . – PANAMA, Pacific coast, Prov. Bocas del Toro, Mouth of Cricamola river,2014, ‘ Variant A’, Ramirez & Buitrago n.s. ( PMA) .

Figures

Fig. 1 Diagnostic characters for Pelliciera rhizophorae and P.benthamii. Occasional intermediate individuals,occurring in sympatric populations,have differing attribute combinations. Measures of length (L) and width (W) used are derived from fresh collection data means.

Fig. 4 Pelliciera rhizophorae Planch. & Triana. a. Habit, Bocas del Toro, Panama; b. leaf stems with paired glands (arrows); c. calyx lobes with multiple nectar glands (arrow); d. leaf margins, narrow edge entire, and wider edge with serrate glands (arrow); e. single foliar bract, narrow edge entire, and wider edge with serrate glands (arrow); f. open flower showing 5 oblong, white petals, whitish paired bracteoles, single green foliar bract, and numerous leaves; g. stem base with sinuous, spreading buttress roots; h. mature fruit capsule; i. pollen grains, some rugose, c. 60 µm diam; j. emergent seedling plumule. — Photos: a–h, j: N.C. Duke; i: J.G. Jones.