Plukenetia sylvestris, Cardinal-McTeague & Gillespie, 2020

24. Plukenetia sylvestris Card. -McTeag. & L.J.Gillespie sp. nov. TYPE: PERU. Cusco. La Convención, Dist. Ocobamba, Versalles, Santa Elena , 1942 m, [-12.78333°, -72.30527°], 24 November 2007, L. Valenzuela, Ciro Astete, F. Zamora, N Suares & M. Atausupa 10453 (holotype: CAN!; isotypes: CUZ, MO!) .

Similar to Plukenetia carolis-vegae Bussmann, Paniagua & C.Téllez but with smaller fruits and seeds and found in natural/ non-cultivated populations from central and southern Peru.

Description —Monoecious lianas; stems erect or twining; older stems dull olive green to brown when dry, to 10 mm in diam, striate, sparsely to moderately puberulous (pubescent); younger stems striate, sparsely puberulous to pubescent. Leaves alternate, evergreen; stipules (narrowly) broadly triangular to deltoid, 0.4–1.5(–2) mm long, persistent but frequently stretched or broken in older stems; petioles 2–7.4 cm long, glabrate to puberulous; blades simple, moderately to broadly ovate (orbicular), 6.5–13.5 3 4.3–11 cm, chartaceous, both surfaces glabrate to puberulous, typically hairier (to pubescent) on major and minor veins, base cuneate, truncate, or rounded (subcordate), margins minutely serrulate (subcrenulate) with small glandular teeth, apex acuminate, tip 0.5–1.5 cm long; venation palmate, primary veins 3, secondary veins 2–4 on each side of the midrib, weakly brochidodromous, tertiary veins percurrent; stipels 1–2 at petiole apex, ligulate or knobby, 0.5–1 mm long; adaxial basilaminar extrafloral nectaries 2, narrowly to broadly elliptic (obovate), typically straddling the margin, 1.3–3.3 3 0.2–1.2 mm; laminar extrafloral nectaries absent. Inflorescences axillary, bisexual racemose thyrses (appearing unisexual if pistillate flowers or staminate axis dropped), 3–14.5 cm long (2–3 cm if staminate axis dropped), 1(2)/axil; peduncle 3.3–25 mm long; axis sparsely puberulous to pubescent; staminate bracts triangular to ovate, 0.5–1.5 mm long, glabrate to puberulous along the margins, bracteoles similar or smaller; pistillate bracts narrowly triangular to deltoid, 0.8–1.4 mm long, glabrate to puberulous along the margins, bracteoles similar or smaller; staminate flowers numerous, distal, 3–15(–18)/node in condensed cymules (thick cyme axes apparent in mature cymules); pistillate flowers 1–4, basal, 1/node (frequently dropped or partly dropped when staminate flowers are at anthesis). Staminate flowers: pedicel 2–7.5 mm long at anthesis, glabrous; buds ovoid to obovoid, apex obtuse to rounded; sepals 4–5, reflexed or spreading at anthesis, lanceolate to ovate, 1.5–3 3 0.5–1.2 mm, apex acute, glabrous; receptacle globose, mostly covered with stamens and nectaries; nectaries of large irregularly shaped segments intermixed between stamens; androecium subglobose and convex, 0.2–1 3 0.6–1.2 mm, stamens 10–18, filaments slender cylindrical, 0.7–1.4 mm long, anthers dorsifixed, anther sacs ellipsoid, dehiscing longitudinally. Pistillate flowers: pedicel (comprising cyme axis and true pedicel) 1–3.2 mm long, glabrate to puberulous; sepals 4, narrowly to moderately triangular, 0.8–1.4 3 0.3–0.6 mm, glabrate; ovary 4-lobed, 0.5–1.8 3 0.7–1.4 mm, lobes rounded and laterally compressed, glabrous to glabrate, conspicuous wings or horns absent; styles 4, partly connate into a squarish column with free style arms spreading at the apex, entire length 5.2–11.5 mm, column width 0.8–1.2 mm, apex width 0.9–4.5 mm, 4-lobed distally, glabrate; free style arms 4, obtuse or spreading (erect), unlobed or slightly 2-fid, 0.8–1.8 mm long; stigmas 4, 0.5–1.3 mm wide, smooth to microverrucose (shortpapillose); flowers developing into fruit similar but larger. Fruits a 4-lobed capsule, squarish in cross-section, 1.9–3.5 3 2.9–3.7 cm, surface dull brown, microverrucose (large irregular verrucae), glabrate, each carpel lobe subglobose and slightly laterally compressed, carinate, keels 0.5–1.8 mm long; stylar columns persistent or not; pedicel (comprising cyme axis and true pedicel) 7–20 mm long. Seeds broadly lenticular, laterally compressed, elliptic to subcircular in outline, 17–19.3 3 17.5–18.5 3 13.4–15.9 mm, ventral surface moderately to obtusely angular, dorsal surface rounded with a radial ridge, dull light brown to yellowish dark brown, with irregular shallow ridges and reticulations; testa persistent. Figure 9 View FIG .

Etymology —The specific epithet is Latin (of the forest), referring to the primary or secondary montane forest where this species is found. It also means wild, which is fitting since we consider P. sylvestris the wild progenitor of the cultivated species P. carolis-vegae .

Distribution, Habitat, and Phenology —This species is known from two disjunct populations from central (Jun´ın and Pasco) and southern (Cusco) regions of Peru ( Fig. 6 View FIG ). They are twining vines and lianas climbing to 10 m in primary and secondary montane forest, sometimes partly disturbed and along roadsides, forest edges, or riparian forest, at (580–) 1280–2440 m elevation. Flowering specimens were collected in February, March and May through September, fruiting specimens from September through February.

Discussion — Plukenetia sylvestris is morphologically similar to P. carolis-vegae but differs by its smaller fruits and seeds (fruits 2.8–3.7 cm in diam and seeds “large” in P. sylvestris compared to fruits 6–10 cm in diam and seeds “extra-large” in P. carolis-vegae )

and stamen number (10–18 in P. sylvestris compared to 25–35 in P. carolis-vegae ; based on species description only, type material of P. carolis-vegae was not available). They also differ in their geographic distribution ( Fig. 6 View FIG ), with P. sylvestris being widespread in central and southern Peru and found in natural habitats and P. carolis-vegae being narrowly distributed in northern Peru and so far only known from its type collection in cultivation. A previous molecular phylogeny based on two plastid (matK, ndhF) and five nuclear (ETS, ITS, KEA 1 introns 11 and 17, TEB exon 17) markers resolved P. sylvestris (referred to as P. cf. carolis-vegae ) in a strongly supported clade sister to P. volubilis ( Cardinal-McTeague et al. 2019a; summarized in Fig. 1 View FIG ). The putative hybrid species P. 3 huayllabambana is thought to have resulted from a cross between P. sylvestris 3 P. volubilis, supported by the introgression of a P. volubilis plastid genome in P. 3 huayllabambana (which otherwise has the nDNA of P. sylvestris ; Cardinal-McTeague et al. 2019a, Fig. S3 View FIG ) in addition to their intermediate staminate flowers (see discussion of P. 3 huayllabambana ). Together, P. carolis-vegae , P. 3 huayllabambana , and P. sylvestris form a high elevation species complex sister to P. volubilis , united by their habitat preference (Andean montane rainforest, 1280–2440 m), floral morphology (staminate flowers with large irregularly shaped interstaminal nectary segments, pistillate flowers with short styles partly connate into a squarish-cylindrical column usually, 10 mm long), typically larger fruits and seeds (fruits 4–10 cm in diam with “extra-large” seeds in P. carolis-vegae and P. 3 huayllabambana ; fruits 2.8–3.7 cm in diam with “large” seeds in P. sylvestris ), and the presence of 1–2 thick stipels at their petiole apex.

The collection Woytkowski 6670 exhibits well preserved floral material (e.g. Fig. 9 View FIG ) but is unusual for having two inflorescences per leaf axis (versus one) and for having basilaminar extrafloral nectaries that are predominantly on the adaxial surface (versus straddling the blade margin).

Specimens Examined — Peru. — CUSCO: La Convención, Dist. Santa Ana , Poromate , [-12.917°, -72.783°], 2118 m, 16 June 2003, Calatayud et al. 1470 ( CAN, MO) ; La Convención, Dist. Vilcabamba, Espiritupampa , [-12.914°, -72.212°], 1544 m, 23 July 2004, Calatayud et al. 2643 ( CAN, MO) ; La Convención, Dist. Santa Ana, Tunquimayo , [-12.909°, -72.813°], 2110 m, 20 September 2004, Calatayud et al. 2746 ( CUZ, MO [accession 4837341, barcode MO-1102090 ; accession 04837342, barcode MO-1102089 ]) ; La Convención, Distrito Santa Ana, Localidad Tunquimayo , [-12.907°, -72.821°], 2007 m, 19 October 2007, Farfán et al. 1820 ( CAN, MO) ; La Convención, Dist. Echarati, Monte Cristo , [-13.5°, -72.317°], 1447 m, 29 July 2005, Huamantupa et al. 6445 ( CAN, MO) ; Ca. 5 km N of Aguas Calientes (km. 116 on railroad), ca. 2000 m, 7 June 1977, Solomon 3166 ( MO [accession 2637789, barcode MO-1381661 ]) ; La Convención, Dist. Occobamba, Santa Elena , [-12.45°, -72.167°], 1995 m, 24 February 2005, Valenzuela et al. 5197 ( CAN, MO) ; La Convención, Dist. Santa Ana, Bosque del Chuyapi , [-12.949°, -72.785°], 2100 m, 19 July 2006, Valenzuela et al. 7297 ( CAN, MO) ; La Convención, Distrito Santa Ana, Tunqui Mayo , [-12.901°, -72.762°], 1870 m, 2 November 2007, Vasquez et al. 33145 ( MO) . — JUNÍN: Yaupi, dept. Junin , 1600 m, 19 July 1961, Woytkowski 6670 ( MO [accession 2154072, barcode MO-1381660 ]) .— PASCO: Oxapampa, Distrito Huancabamba, Zona de Amortiguamiento del Parque Nacional Yanachaga-Chemillén , sector Tunqui , [-10.287°, -75.523°], 1753 m, 13 September 2007, Castillo et al. 965 ( CAN, MO) ; Cordillera Yanachaga, E of Oxapampa,lumber road to Chacas microwave station, 10 km E of main road, [-10.583°, -75.25°], 2040–2110 m, 2 March 1982, Gentry & Smith 35906 ( MO [accession 2983786, barcode MO-1381639 ]) ; Oxapampa, Distrito Oxapampa, Parte alta de la quebrada San Luis , [-10.565°, -75.345°], 2440 m, 30 May 2007, Monteagudo et al. 14125 ( CAN, MO) ; Oxapampa, Distrito Huancabamba, Parque Nacional Yanachaga-Chemillén , Sector Tunqui , [-10.289°, -75.518°], 1790 m, 22 September 2007, Monteagudo et al. 15253 ( CAN, MO) ; Oxapampa, Dist. Villa Rica, Palma Centro Bocaz , camino a Alto Atarraz-Zona de Amortiguamiento , Parque Nacional Tanachaga-Chemillén , [-10.65°, -75.193°], 1515 m, 14 January 2005, Ortiz et al. 191 ( CAN, MO) ; Oxapampa, Distrito Villa Rica, Localidad Centro Bocaz , [-10.633°, -75.167°], 1280 m, 17 September 2003, Perea et al. 282 ( CAN, MO) ; Oxapampa, Dist. Oxapampa, Abra Villa Rica , [-10.4°, -75.183°], 2000 m, 26 August 2005, Rojas et al. 3863 ( CAN, MO) ; Oxapampa, Distrito Pozuzo, Camino de Puente Victoria hacia la Comunidad Nativa Alto Lagarto, [-10.1°, -75.433°], 700 m, 29 September 2007, Rojas et al. 4648 ( MO [accession 6126857, barcode MO-2131172 ], USM) ; Oxapampa, Dist. Palcazú, Comunidad Nativa de Alto Lagarto , [-10.199°, -75.356°], 700 m, 3 December 2007, Rojas et al.4827 ( CAN, MO) ; Oxapampa, Dist. Pozuzo, Alto Lagarto a Puente Victoria , [-10.1°, -75.433°], 700 m, 28 December 2007, Rojas & Ortiz 5152 ( CAN, MO) ; Oxapampa, Dist. Palcazú, Comunidad nativa Alto Lagarto - Reserva Comunal Yanesha. , [-10.152°, -75.392°], 584 m, 30 October 2009, Rojas & Ortiz 7102 ( CAN, MO) ; Oxapampa, Road from Oxapampa to San Alberto , [-10.533°, -75.35°], 2250 m, 20 June 2003, van der Werff et al.17532 ( CAN, MO) ; Oxapampa, Along old road Oxapampa-Villa Rica , [-10.633°, -75.367°], 2000 m, 25 June 2003, van der Werff et al. 17759 ( CAN, MO), 17760 ( CAN, MO) ; Oxapampa, Distrito Bermudez, Bosque Protección San Matias-San Carlos , Sector Unión- Shimaki , [-10.75°, -74.917°], 1382 m, 12 February 2003, Vasquez et al. 27906 ( HUT, MO [accession 5709828, barcode MO-300971 ], USM) .