Begonia nunezii Moonlight, 2023

Moonlight, Peter. W., Jara-Muñoz, Orlando A., Purvis, David A., Delves, Jay, Allen, Josh P. & Reynel, Carlos, 2023, The genus Begonia (Begoniaceae) in Peru, European Journal of Taxonomy 881, pp. 1-334 : 269-271

67. Begonia nunezii Moonlight sp. nov.

urn:lsid:ipni.org:names:77323296-1

Figs 84B , 86

Diagnosis

Most similar to B. leptostyla Irmsch. but differing in its densely hispid indumentum (vs sparsely to densely tomentose indumentum) with much longer hairs (ca 2 mm long vs 0.5 mm long); its larger stipules (10–12 × 4–6 mm vs 4–8 × 1–3 mm); its leaves, which are twice as long as broad (vs [2.5–]3–4 times as long as broad); and its bifid styles (vs bifid to irregularly multifid).

Etymology

We are delighted to name this species in honour of Percy Núñez, the Peruvian ethnobotanist who made all of the known collections of the species.

Type

PERU – Cusco Region: Prov. La Convención • Dist. Echarate, Segakiato in the Camisea River , lower Urubamba Region; 11°48′30″ S, 72°53′ W; 320 m a.s.l.; 2 Oct. 1997; P. Núñez 20940; holotype: USM ; isotype: US [ US00625236 ].

Specimens examined

PERU – Madre de Dios Region: Prov. Manu • Cocha Cashu ; [11°45′ S, 71°58′ W]; 400 m a.s.l.; 4 Oct. 1985; P. Núñez 1944; US [ US00222349 ]. – Prov. Tambopata • Tahuamanu , río Pariamanu ; 12°23′35″ S, 69°21′36″ W; 200 m a.s.l.; 8 Aug. 1995; P. Núñez 17306; USM, WAG [2: WAG1576527 , WAG1576528 ].

Description

Caulescent herb, to 1.5 m high. Stem erect, rarely branching; internodes to 9 cm long, to 5 mm thick, succulent, colour unknown, densely hispid. Stipules persistent, triangular, 10–12 × 4–6 mm, apex acute, translucent, colour unknown, sparsely hispid, margin entire, long-ciliate. Leaves 4–6, alternate, basifixed; petiole 1.8–8 cm long, colour unknown, densely hispid; blade asymmetric, ovate, to 14 × 7 cm, membranaceous, apex acuminate, base obliquely cordate, basal lobes not overlapping, sinus to 18 mm deep, margin irregularly serrate, ciliate, upper surface colour unknown, sparsely hispid, lower surface colour unknown, densely hispid on the veins, glabrous on the lamina, veins palmate-pinnate, ca 6 veined from the base, with 2–4 secondary veins on the larger side, 1–3 secondary veins on the smaller side. Inflorescences 1–3, axillary, erect, cymose, with 6 branches, bearing up to 16 staminate flowers and up to and 32 pistillate flowers, protandrous; peduncle to 11 cm long, colour unknown, densely hispid, bracts deciduous, lanceolate, 6–10 × 2–3 mm, translucent, colour unknown, glabrous, apex acute, margin entire, ciliate. Staminate flowers: pedicels to 10 mm long, densely hispid; tepals 2, spreading, broadly ovate, 5–9 × 5–8 mm, apex rounded, white, glabrous, margin entire, aciliate; stamens ca 25 projecting, yellow, filaments ca 1 mm long, free, anthers elliptic, c2.5 × 0.5 mm long, dehiscing via lateral slits, connectives extending to 0.1 mm, symmetrically basifixed. Pistillate flowers: pedicels to 30 mm long; bracteoles 2, directly beneath the ovary, obovate, 6–7 × 3–5 mm, apex obtuse, transparent, colour unknown, glabrous, margin entire, long-ciliate; tepals 5, subequal, deciduous in fruit, spreading, the largest ovate, 5–8 × 2.5–5 mm, apex rounded, white, glabrous, margin entire, aciliate, the smallest elliptic to ovate, 4–7 × 1.5–4 mm, apex rounded, white, glabrous, margin entire, aciliate; ovary body ovoid, 4–7 × 3–5 mm, colour unknown, glabrous, unequally 3-winged, wings triangular, largest 6–9 × 3–9 mm, smallest 5–9 × 2–6 mm; 3-locular, placentae unknown; styles 3, yellow, free, 1.5–5 mm long, once-divided, stigmatic papillae in a spirally twisted band. Fruiting pedicel to 25 mm long. Fruit body ovoid, to 15 × 11 mm, drying light brown, wings same shape as in ovary, the largest expanding to 28 × 12 mm, the smallest expanding to 20 × 10 mm.

Proposed conservation assessment

Known from three populations 390 km apart in lowland Amazonia and last collected in 1997. The most southerly collection was made <1 km from a small scale and presumably illegal gold mine, which satellite imaging shows was dug between 2004 and 2012 and expanded from 2017 to 2018. There is however ample riverside habitat remaining and a vast area of under-collected Amazonian forest both between and around all three populations. We assess B. nunezii sp. nov. as Data Deficient (DD).

Notes

Begonia nunezii sp. nov. is part of a group distinguished from other South American members of B. sect. Ruizopavonia by their densely tomentose or hirsute indumentum and persistent stipules. All Bolivian endemic members of the section are part of the group and B. nunezii sp. nov. is the first such species found outside of Bolivia. Several members also have multifid rather than bifid styles, though this can vary even within species. Begonia nunezii sp. nov. is unique within this group as the only species with transversely ovate leaves and palmate-pinnate venation. No members of the group have been included in any molecular phylogenies, so were tentatively placed in B. sect. Ruizopavonia by Moonlight et al. (2018). We also tentatively place B. nunezii sp. nov. in this section.

Identification notes

Begonia nunezii sp. nov. is most similar to Bolivian B. leptostyla (see Diagnosis) but could also be confused with the Bolivian species B. bangii . This species shares the densely long-hispid indumentum of B. nunezii sp. nov. but differs in its reniform to orbicular stipules. Like B. leptostyla , B. bangii also has leaves that are usually more than three times as long as broad. Within Peru, identifying B. nunezii sp. nov. is simple, as it is the only erect or climbing herb with a dense indumentum that is found in lowland Amazonia.

Distribution and ecology

Endemic to Peru and known from Madre de Dios and Cusco Regions ( Fig. 84B ). Found in Amazonian forest at an elevation of 200–320 m a.s.l. All collections of this species were made on the banks of small rivers, and we assume from its habit that it climbs through riverside vegetation. Begonia nunezii sp. nov. has been collected in flower in October and in fruit in August.

Figures

Fig. 84. Distribution of Begonia sect. Ruizopavonia A.DC. in Peru and surrounding countries. A. B. glauca (Klotzsch) Ruiz & Pav. ex A.DC. (red) and B. yuracyacuensis Moonlight sp. nov. (blue). B. B. nunezii Moonlight sp. nov. (red) and B. peruviana A.DC. (blue). Black lines indicate country borders, grey lines indicate major administrative divisions, blue lines indicate rivers, and shading indicates elevation.

Fig. 86. Begonia nunezii Moonlight sp. nov. A. Habit, including insets of upper and lower leaf indumentum. B. Staminate flower, front view. C. Staminate flower, side view. Illustration by Anna Dorward from P. Núñez 20940 (US).