Pourouma bergii Gaglioti & Romaniuc, 2014

Gaglioti, André Luiz & Neto, Sergio Romaniuc, 2014, Pourouma bergii (Urticaceae), a new species from South America, Phytotaxa 173 (2), pp. 168-172 : 169-170

Pourouma bergii Gaglioti & Romaniuc , spec. nov.

Affinis Pourouma tomentosa subsp. persecta et P. petiolulata sed ramulis glabris, perianthio masculo infundibuliformi (nec urceolato neque e tepalis liberis constanti), staminibus 2 (nec 4), perianthio foemineo tomentoso (nec velutino neque hispidulo) differt.

Type: — PERU. Loreto: Prov. Alto Amazonas, Andoas, campamento petrolero, Río Pastaza , no. de Iquitos, 2º55’S, 76º25’W, 210 m, 21 November 1980 (♀), Vásquez & Jaramillo 809 (holotype: MO!, isotypes: BG!, F!, NY!)

Tree, 8–25 m tall, 10–28 cm dbh, with stilt roots. Leafy twigs 5–12 mm diam., glabrous, not fistulous, releasing a watery exudate when cut, the exudate turning black on exposure to air; internode 5–22 mm long. Lamina palmatisect 10.5–40.5 × 10–38.5 cm, venation palmate; 5–7 segments, with incisions down to the petiole and segments, pseudopetiolules 5–12 mm long; segments lanceolate to elliptic, 5–19.5 × 3.5–8.5 cm, coriaceous, apex acuminate, margin with indument sparsely yellowish, sericeous, hairs 0.1–0.4 mm long, base acute; adaxial lamina surface smooth, indument of primary vein yellowish, sericeous, hairs 0.1–0.4 mm long; abaxial lamina surface smooth, with indument yellowish, sericeous, hairs 0.1–0.4 mm long, and sometimes with indument sparsely white, arachnoid, on the veins, hairs 0.2–20 mm long; secondary veins in the mid-segment 14–26 pairs, basal pair unbranched, diverging from the midrib, born at an angle of 50°–60°; tertiary and quaternary veins reticulate, slightly prominent, with indument white, arachnoid in the areoles, hairs 0.2–20 mm long; petiole 3.5–18.5 (–26) cm long, glabrous to subglabrous, sometimes with indument sparsely white, arachnoid in the juvenile leaves, hairs 0.2–20 mm long; stipules 3–11.5 cm long, abaxial surface with indument yellowish, sericeous, hairs 0.1–0.4 mm long, and with indument sparsely white, arachnoid, hairs 0.2–20 mm long, adaxial surface with indument sparsely yellowish, sericeous, hairs 0.1–0.4 mm long, to glabrous, caducous. Staminate inflorescences 5.5–10.5 × 2.5–6.5 cm, 2–3–branched; peduncle 1.5–2.5 cm long, peduncle and branches with indument yellowish, velutinous to hirtellous, hairs 0.2–0.5 mm long; flowers ca. 250–650, flowers organized in 15–50 glomerules; glomerule 4–6 mm diam. Staminate flowers 2.2–3.2 × 0.8–1.5 mm, sessile; perianth 1.2–1.8 × 0.8–1 mm, infundibuliform, tepals connate, with indument whitish, sericeous, hairs 0.1–0.4 mm long; 2–stamens, filaments 1.5–2 mm long, free, filaments exceeding the perianth. Pistillate inflorescence unknown. Infructescence 6.5– 9 × 4.5–6.5 cm; peduncle 3–4.5 cm long, peduncle and branches glabrous or with indument sparse white arachnoid, hairs 0.2–20 mm long; fruits 6–8, organized in 2–3 cymes; pedicels 8-15 mm long; stigma peltate, 8– 1 mm diam., sometimes with indument yellowish, sericeous. Fruiting perianth 10–18 × 5–10 mm, ovoid to ellipsoid, brown to vinaceous, with indument yellowish to whitish, sericeous, hairs 0.1–0.4 mm long, and with indument white, arachnoid, hairs 0.2–20 mm long. Achene 8–15 × 3–8 mm, glabrous. Seed 5–10 × 2–5 mm, ovoid, brown to vinaceous.

Distribution, habitat & ecology: —Northeast of Peru (Loreto and Pasco) and Ecuador (Napo and Pastaza), in primary terra firme forest of the Amazonian region, in lowland moist area, at an elevation of about 200 to 365 m above sea level.

Etymology:— The epithet honors Dr. Cornelis Christiaan Berg (1934–2012†), a great specialist botanist in Moraceae , Cannabaceae , Ulmaceae and Urticaceae .

Local name: —It is known as ‘yohue’ by Huaorani from Pastaza, Ecuador.

IUCN conservation status: — Pourouma bergii is known from only seven collections in the provinces of Loreto, Pasco ( Peru), Napo and Pastaza ( Ecuador), made between 1980 and 1994. However, the extent of occurrence of P. bergii is ca. 96,000 km 2 and the population size are unknown. For these reasons P. bergii is assessed as Data Deficient (DD) according to IUCN Red List criteria ( IUCN 2013).

Additional specimens examined:— ECUADOR. Napo: Orellana, Parque Nacional Yasuni , carretera y oleoducto de Maxus en construcción, km 54–58, 0º48’S, 76º30’W, 250 m, 26–30 September 1993 (♂), Aulestia et al. 745 ( MO!) ; carretera y oleoducto de Maxus en construcción, km 40, 0º39’S, 76º26’W, 250 m, 7 September 1994 (♀), Aulestia et al. 2698 ( MO!) ; Aiñangu, NW corner of the Parque Nacional Yasuni, 0º33’S, 76º22’W, 355–365 m, 1–15 February 1986 (♀), Korning et al. 47618 ( AAU!, BG!, MO!, NY!) ; Canton Francisco de Orellana, Via de los Zorros , pozo petrolero Jaguar I, 40 km al SW de Coca , 0º44’S, 77º05’W, 250 m, 23 October 1988 (♀), Palacios 3238 ( BG!, MO!) . Pastaza: Pastaza Canton, Pozo petrolero Moretecocha de Arco , 01º34’00”S, 77º25’00”W, 580 m, 4–12 October 1990 (♀), Gudiño et al. 958 ( MO!, NY!) . PERU. Pasco: Prov. Oxapampa. Distrito Iscozacín , 22 september 1986 (♂), Pariona et al. 954 ( BG!, F!, MO!) .

Discussion: — Pourouma bergii belongs to the group of species with palmatisect laminae. It shows similarities to P. tomentosa subsp. persecta C.C. Berg & van Heusden (1988: 108) and P. petiolulata C.C. Berg (1993: 100) : palmatisect lamina with segments usually pseudo-petiolules ( Figs 1A–B ). It may be distinguished from P. petiolulata by glabrous leafy twigs (versus hirsute), infundibuliform staminate perianth ( Figs 1E , 2A ) (versus perianth urceolate or with free tepals) and tomentose pistillate perianth with white arachnoid indument ( Figs 2 C–D ) (versus yellow velutinous or hispidulous, see Table 1.)

The related species P. petiolulata is endemic of Napo ( Ecuador) and P. tomentosa subsp. persecta occurs in the Bolivia (Cochabamba and La Paz), northwest of Brasil (Amazonas, Acre and Mato Grosso).

Figures

FIGURE 1. Pourouma bergii. A. Leafy twig with infructescence. B. Leaf, abaxial surface. C. Indument of the pistillate perianth. D. Staminate inflorescence. E. Staminate flower.A–C from Vásquez et al. 2809 (MO) and D-E from Aulestia et al. 745 (MO). Scale bar:A = 2 cm; B = 1 cm; C = 0.5 mm; D = 1 cm; E = 1mm. Drawn by Klei Sousa.

FIGURE 2. Pourouma bergii. A. Staminate flower. B. Indument sericeous of the staminate perianth. C. Fruiting perianth, fruit and pedicel.D. Indument.sericeous of the fruiting perianth.A–B from Aulestia et al. 745 (MO) and C–D from Vásquez et al. 2809 (MO). Scale bar: A = 1 mm; B = 50 µm, C = 5 mm, D = 100 µm