Paullinia decorticans Somner & Acev.-Rodr., 2018

Acevedo-Rodriguez, Pedro & Somner, Genise Vieira, 2018, New species of Paullinia (Sapindaceae) from continental tropical America, PhytoKeys 114, pp. 95-113 : 95

Paullinia decorticans Somner & Acev.-Rodr. sp. nov. Fig. 2

Diagnosis.

Paullinia decorticans shares with P. martinellii Acev.-Rodr. & Somner the presence of bulbous axillary buds with large cataphylls and large overlapping bracts. However, P. decorticans differs from P. martinellii by the sericeous-lanate, glabrescent stems with defoliating bark (vs. tomentulose, glabrescent, without defoliating bark), the subulate 3-4 cm long stipules (vs. ovate to cordiform and clasping the stem, 3-5 cm long) and the depressed globose, sessile, puberulous fruits (vs. ellipsoid, long attenuate at the base and hirtellous).

Type.

ECUADOR. Napo; Yasuní National Park, 44-45 km along Maxus Petroleum Road, growing on trees along roadside, terra firme forest, 00°40'S, 76°23'W, 200-300 m elev., 18 Jan 1998 (fl, fr), Burnham 1551 (holotype: US!; isotype: F!, QCA!)

Description.

Liana climbing on trees. Young stems sericeous-lanate, with beige, straight, trichomes, 5-8 mm long; mature stems to 3.3 cm diam., sub-terete, furrowed, glabrous, light brown, with lines of lenticels, producing abundant milky latex; bark thin, defoliating in small, rectangular plates; cross section simple, with solid medulla and lobed xylem. Axillary buds bulbous, ovoid, 8-25 mm long; cataphylls numerous, overlapping, acrescent, 5-10 × 1-3 cm, oblong, membranaceous, furfuraceous and sericeous. Stipules subulate 3-4 cm long, abaxially sparsely sericeous, early deciduous. Leaves pinnately 5- or 7-foliolate; petioles and rachis naked, sericeous when young, becoming glabrous and striate, with defoliating, thin epidermal layer; petioles 3-16(24.5) cm long; rachis 3-7.5(17) cm long; distal petiolules 5-15 mm long, lateral and basal petiolules 5-10 mm long; leaflets 9-14 (20) × 3-5 cm, chartaceous, elliptic, oblong or less often lanceolate or oblanceolate, adaxially glabrous, abaxially sparsely sericeous along primary and secondary veins, attenuate at base on distal leaflet, obtuse or rounded and asymmetrical on lateral leaflets, caudate at apex, with entire or undulate margins, venation brochidodromous, tertiary venation percurrent between secondary veins. Thyrses axillary, spicate, 5-14 cm long, axis robust, shortly flavo-tomentose, without tendrils; bracts 7-10 mm long, deltate-ovate, coriaceous, abaxially shortly flavo-tomentose, overlapping; cincinni 4- to 6-flowered, sessile; bracteoles 3-5 mm long, deltate-lanceolate, coriaceous, abaxially shortly flavo-tomentose; pedicels ca. 3 mm long, shortly flavo-tomentose, articulate in upper third. Sepals 5, shortly flavo-tomentose, concave, coriaceous, the outer sepals ovate, ca. 5.5 mm long, inner sepals suborbicular, 7-7.5 mm long, the two anterior sepals connate ca. ½ of their length; petals elliptic, ca. 12 mm long, atrolineate, acuminate at apex; appendages ca. 8 mm long, crest fleshy, bifurcate; nectary 2- or 4-lobed, glabrous, posterior lobes rectangular, brownish, ca. 2 mm long, anterior lobes deltate, ca. 1 mm long, or obsolete; torus flavo-tomentose; filaments densely lanate; gynoecium ca. 5.5 mm long, ovary trilobed-ellipsoid, densely ferruginous-tomentose. Capsule ellipsoid to globose-trilobed, unwinged, reddish, 3-4 × 2.2-3 cm, woody, puberulent or glabrous, sessile, apiculate at apex; pericarp ca. 8 mm thick. Seeds 1 to 3 per capsule, trigono-ellipsoid (with 2 flat sides), ca. 2.5 cm long, testa dark brown, dull, without arillode.

Distribution and ecology.

Known from NW Amazonia, in Ecuador and Peru in non-flooded, dense forest 140-400 m elevation.

Phenology.

Collected in flower in May, December and January and in fruit from December to January.

Etymology.

The specific epithet refers to the defoliating bark and epidermis of leaf axes present in the new species.

Conservation status.

Although Paullinia decorticans is known from few collections, they come within an EOO of ca. 80,000 km2, which include the Yasuní National Park and densely forested areas within Loreto, Peru. Given the low level of threats associated with this vast region, this species is here treated as least concern (LC) within IUCN guidelines.

Additional specimens examined.

ECUADOR: Napo. Parque Nacional Yasuní, Pozo petrolero Daimi 2, primary humid, partly flooded forest along river, 00°55'S, 76°11'W, 200 m elev., 26 May– 8 Jun 1988 (fl), Cerón & Hurtado 4167 (US). Pastaza. Petroleum well Villano 2 de Arco, primary, humid forest, 01°25'S, 77°20'W, 400 m 1-18 Dec 1991 (fl), Hurtado 2819 (MO), Mun. Puyo; Los Vencedores, Experimental Station ESPOCH, ca. 30 minutes by car, S of Puyo, premontane rainforest, 1°30'S, 77°56'W, 13 Dec 1995 (fl, fr), Soerjato et al. 9392 (F). Orellana. Parque Nacional Yasuní, Parcela permanente de 50 ha del Proyecto "Dinamica del Bosque Yasuní a 1 km de la estación Científica del Yasuní, bosque muy húmedo, 0°41'00"S, 76°24'10"W, 230 m elev., 31 May 2006 (st), Romero-Saltos et al., 2583 (QCA). PERU. Loreto. Quebrada Sucursari, (N side tributary of Río Napo), mature terra firme forest, 3°15'S, 72°55'W, 140 m elev., 14 Jun 1986 (st), Gentry et al. 54367 (MO); Maynas. Explorama Lodge ½ way between Indiana and mouth of Napo river, mature forest on lateritic soil, 3°28'S, 72°50'W, 140 m elev., 5 Jan 1991 (st), Gentry el al 72124 (MO); vicinity of Aguaytía, woods, 1 Jul 1967 (st), Mathias & Taylor 5076 (F), Pto Alianza, Tamshiyacu creek, primary forest, 04°08'S, 72°55'W, 160 m elev., 28 May 1981 (fr), Vásquez & Criollo 1804 (US), Explorama Inn, ca. 2 km W of Indiana on Rio Amazonas, well-drained forest on good soil, 3°30'S, 73°02'W, 130 m elev., 14 Feb 1987 (st), Gentry et al. 55862 (F, MO), Iquitos, seasonally flooded, primary forest, 04°10'S, 73°30'W, 150-180 m elev., 6 Jul 1991 (st), Vásquez & Jaramillo17138 (MO).

Vernacular name.

Equador. Pastaza: Chunda (fide Hurtado 2819), Macote (fide Mathias 5076).

Discussion.

Paullinia decorticans differs from P. martinellii , the only other species of Paullinia with bulbous axillary buds with large cataphylls and large overlapping bracts by the features discussed in the diagnosis. Paullinia decorticans is the only species within the genus recorded as having defoliating bark and defoliating leaf rachis epidermis.

Figures

Figure 2. Paullinia decorticans. A Fruiting branch B Detail of abaxial surface of leaflet C Insertion of two basal leaflets showing defoliating rachis and petiole D Axillary shoot with overlapping cataphylls E Bulbous, young axillary shoot covered by cataphylls F Stipule G Staminate flower, lateral view H Posterior petal, dorsal view I Posterior petal with appendage, frontal view J Staminate flower with removed perianth showing nectary lobes and stamens, posterior view K Axillary infructescence with a fruit L Seed, ventral view. A, B, E, G-J from Burnham 1551 (US) C from Ceron & Hurtado 4167 (US) D from Vasquez & Jaramillo 17138 (MO) F from Hurtado 2819 (MO) K, L from Vasquez & Criollo 1804 (US).