Holotype: Cuba, Pinar del Río province, Viñales municipality: “Parque Nacional Viñales, Sierra de La Caoba, ladera norte hacia Cañadones”, 225 m, “sobre carso de mogote, individuo único”, 3 Aug 2011, Ramiro Chaves HAC43069 (HAC [with flowers]; isotypes: B, HAC, HAJB [2 sheets], JE, PAL-Greuter).

Description — Trees 14 m tall; trunk forming a straight shaft, 23.5 cm in diam, at 1.3 m above base; branches few; bark reddish to pinkish pale brown at base of tree, to ashy pale brown or pale grey toward apex of tree. Leaves 3-pinnate, sometimes 4-pinnate (Fig. 3A–G), 30–100 cm long, 25–80 cm wide; stipules adnate to base of petiole, lanceolate, 2–4 mm long from confluence on petiole to apex, subcoriaceous, glabrous; petiole 7–30 cm long; rachis articulated at nodes; pinnae generally imparipinnate; accessory pinnae or leaflets (terminology based on Wen 2011) commonly present at point of insertion of 1st-and sometimes of 2nd-order leaf branches (could be also considered minor digitate pinnae or leaflets of a pinnatedigitate leaf in mid-transition to 3-pinnate), sometimes present even up to 5th node of rachis; leaflets of varying size and shape according to their position; petiolule proximally articulated to rachis or rachilla and usually distally articulated a little below lamina, glabrous, length variable according size and position, 1–40 mm long, those in terminal leaflets usually longest; leaflet laminas light green abaxially, green with some shine adaxially, generally ovate, oblong-ovate, or ovate-lanceolate, but sometimes orbicular, oblong, or lanceolate, 1.4–9.5 cm long, 0.9–5.5 cm wide, membranous, glabrous, base generally rounded or subcordate, sometimes cordate or obtuse, rarely acute, usually briefly contracted near petiolule, margin varying according to leaflet size, proximally entire, elsewhere variable from subentire to serrate (from minutely and sparsely to broadly serrate) or crenate, or crenateserrate, depending on presence of 4–8 denticles on each side (Fig. 2P), more evident on immature leaflets (Fig. 3H), apex acuminate, frequently longish. Inflorescence lateral, solitary or 2 or 3 aggregated on a short leafless stem, paniculate; main axis light brown, 5–10 cm long, 4–6 mm wide, conspicuously lenticellate, glabrous, with 1 or 2 whorls of umbels, proximal whorl (if present) with up to 3 umbels, distal whorl with 4–8 umbels; peduncle predominantly greenish brown, articulated near middle, widening toward hemispherical apex, 6.5–10 cm long, 2–5 mm wide, rough, lenticellate; bracts subtending individual umbels, persistent, triangular, 2–3 mm long, 3–5 mm wide, coriaceous, glabrous; bracteoles persistent, triangular, 0.4–1.5 mm long, 0.3–1.5 mm wide; umbels 39–60-flowered. Flowers hermaphroditic, appearing after emergence of late leaves, nearly odourless; pedicels mostly purplish red with very thin longitudinal streaks, except light green at base and sometimes at apex, articulated to thalamus, at anthesis 15–27 mm long, c. 1 mm wide at base, c. 0.5 mm wide at middle, glabrous; thalamus light green, parabolic cupuliform, 2.5–3.2 mm long, c. 1 mm wide at base, 2.5–3.5 mm wide at apex; sepals 4 (or 5), minute triangular denticles on calyx rim, c. 0.1 mm long; petals (5 or)6(or 7), free, imbricate in bud, caducous, changing from light green to yellowish white before anthesis, externally sometimes irregularly purplish tinged, adaxially yellowish white at anthesis, tongue-shaped, 3.5–5 mm long, 1.5–2.2 mm wide, with a thickened medial line, basal ½ recurved, apex incurved, more internal petals with incurved apex; stamens (5 or)6, caducous; filaments narrowing toward apex, 4–5 mm long, 0.5–0.7 mm wide at base, 0.1–0.2 mm wide at apex, terminal bent before anthesis; anthers oblong, 2–3 mm long, base subsagittate, divergent; nectar disk light yellowish green, irregularly rough; ovary inferior, (5 or)6-locular, c. 2.5 mm long, 1.5–2 mm in diam.; styles firmly connate into a thick fleshy column with a truncate apex, c. 1 mm long; stigmas (5 or)6, almost rudimentary, green. Fruit changing at maturity from green to purplish red and finally to dark purple or almost black, globose, 7–11 mm long, 7–11 mm in diam., with 5 or 6 ribs when dry; styles stout, persistent stigmas almost circular, margins divergent toward apex, laterally usually attached. Seeds 6 or 5 per fruit, very light yellowish brown, flattened, almost semi-circular in outline, 5–6 mm long, 3–3.5 mm wide, 0.6–0.9 mm thick, base rounded, hilum margin almost straight, apex acute; testa slightly undulate; embryo evident as a linear thickening 1.5–3 mm long almost from centre to apex of seed.

Phenology — Tree leafless from December or January to April (Fig. 4B); new leaves flushing from April or May to July; flowering from mid-July to mid-August; fruit ripening late September to late October.

Distribution — Endemic to Cuba, Pinar del Río province, Viñales municipality, Viñales National Park, N flank of Sierra de La Caoba facing the Cañadones valley (Fig. 1), where only one individual is known.

Habitat — Aralia duplex grows in semi-deciduous forest of the “Mogote” (karstic hill) vegetation complex, with an open canopy, on karstic limestone with a little soil present in the interstitial cavities, on a 25°–30° slope, at 225 m altitude. Neighbouring trees are up to 16 m tall and rarely exceed 25 cm in diam. at 1.3 m above the base. The surrounding vegetation has been listed by Lazcano Lara & Areces Berazaín (2005). See Fig. 4.

Etymology — The specific epithet, duplex, is a Latin adjective meaning twofold or double, chosen because the number of native Cuban Aralia species has been doubled by the discovery of A. duplex.

Additional specimens examined (paratypes) — Cuba, Pinar del Río province, Viñales municipality: same locality and from same individual as holotype, 28 Oct 2004, F. Areces & J. Lazcano HFC 83079 (HAJB [5 sheets, sterile]); ibid., 16 Jul 2010, Ramiro Chaves HAC43071 (HAC [2 sheets, immature leaf, sterile]); ibid., 26 Oct 2010, Ramiro Chaves HAC43070 (HAC [with fruits]).