Begonia jocotocoi Á.J. Pérez & Tebbitt, 2024

Pérez, Álvaro J., Mena-Olmedo, Patricio, Cabrera, Leovigildo, León, José & Tebbitt, Mark C., 2024, A new endemic Begonia species (sect. Knesebeckia, Begoniaceae) from the south-western montane forest remnants of Ecuador, Phytotaxa 666 (3), pp. 216-222 : 217-221

Begonia jocotocoi Á.J. Pérez & Tebbitt , sp. nov. § Knesebeckia ( Figs 1–2 ).

Type: — ECUADOR. El Oro: Cantón Santa Rosa, Parroquia Torata, Reserva Buenaventura , Fundación Jocotoco , sector Sambotambo-Birón , 03°33’54.7”S 79°46’47.5”W, 1300–1400 m, 7 May 2022, Pérez et al. 11782 (holotype QCA [249522]!; isotype LOJA!) .

Begonia jocotocoi morphologically resembles B. serotina , but can be easily differentiated by the dense red long trichomes covering the petioles and the lower surface of leaf lamina that turns purple at maturity (vs. petiole glabrous to puberulous and lower surface of leaf lamina pale green); leaf laminae that are minutely bullate (vs. smooth); larger stipules (1.2–2.2 × 1.1–1.8 cm vs. 1.1–1.3 × 0.4–0.8 cm); presence of paired bracteoles directly beneath the pistillate flowers (vs. bracteoles absent), and pedicels and also sometimes the abaxial surfaces of most floral whorls sparsely covered with glandular hairs (vs. glabrous to puberulous).

Perennial caulescent herb; stem to 40 cm long, basal portion producing roots along its length and either growing erect or pressed against the soil and the apical portion aerial for up to 20 cm, 0.8–2.5 cm diam., stem unbranched; stipules persistent, ovate, 1.2–2.2 × 1.1–1.8 cm, apex acute, arista ca. 3 mm long, margin entire, glabrous. Leaves few, 1 to 5, spirally clustered towards the stem apex, peltate; petioles 7–15 cm long, green, with dense red 3–6 mm long trichomes; lamina subsymmetric, usually orbicular-ovate, occasionally elliptic-ovate, 9.5–17 × 7.8–11 cm, papery, upper surface of leaf lamina deep green and minutely bullate with hairs in center of bullae, veins impressed, lower surface of leaf lamina purple, with dense red long trichomes, apex acuminate, margin minutely denticulate, veins radiating out from central point, 7 to 8. Inflorescences: 1 to 2, axillary, arising from apical portion of rhizome, held erect, a dichasial cyme, branching up to six times, ca. 10–15-flowered, protandrous; peduncle 40–50 cm long, glabrous or with a very sparse cover of glandular hairs in the upper 5 cm portion, primary branches 1.5–5.5 cm long, sparsely covered with glandular hairs, secondary branches 1–2.5 cm long, sparsely covered with glandular hairs; pedicels of staminate flowers 0.6–1.8 cm long, sparsely covered with glandular hairs; pedicels of pistillate flowers 0.6–1.5 cm long, sparsely covered with glandular hairs; bracts persistent, obovate to ovate, 3–7(–9) × 2.5–6(–7) mm, apex subacute, margin entire, sparsely covered with glandular hairs to glabrous on the abaxial side. Staminate flowers: tepals 4, spreading, white, white with pale pink tinged veins, pink or pale red, margins entire, outer pair oblong-elliptic, 1.6–2.2 × 0.8–1.2 cm, apex obtuse, base rounded, sparsely covered with glandular hairs to glabrous on the abaxial side, inner pair orbicular to suborbicular, 1.5–2 × 1.7–2 cm, apex rounded, base tapering; stamens 32 to 41, attached along the length of a 0.5–1 mm tall torus and also around base of torus; filaments 1–3 mm long; anthers obovate, 0.5–1 mm long, dehiscing by unilateral slits, connectives widening at apex but not projecting, symmetrically basifixed. Pistillate flowers: bracteoles paired directly beneath ovary, sparsely covered with glandular hairs to glabrous on the abaxial side, differing in shape, ovate or broadly ovate to obovate, 7–8 × 8–10 mm, apex obtuse to rounded, often shallowly notched, margin entire; tepals 5, spreading, same colour as staminate flowers, margins entire, outer 3 oblong-elliptic, 0.9–1.5 × 0.5–0.7 cm, apex rounded or subacute, base rounded to rounded-attenuate, sparsely covered with glandular hairs to glabrous on the abaxial side, innermost oblong-elliptic or ovate-elliptic, 1–1.5 × 0.6–1.1 cm, apex rounded or subacute, base attenuate, glabrous; ovary body trigonous-ellipsoid, 0.5–0.7 × 0.4–0.5 cm, initially white with a pink tinge but becoming pale green, sparsely covered with glandular hairs to glabrous, subequally 3-winged, wings subdeltoid, front edge of wings ± truncate, from there slightly curving downwards until in line with base of ovary body, apex acute to rounded, 4–7 × 6–9 mm, 3-locular; styles 3, free to base, yellow, 2–3 mm long, bifid from about 2/3 their height, branches ± erect, stigmatic papillae in a spiral band. Fruits not seen.

Etymology:— The new species is named in honor of the Jocotoco Foundation to recognize the foundation’s effort to preserve the natural richness of the Ecuadorian forests through the establishment of 16 nature reserves covering more than 36000 ha of forest remnants.

Distribution, habitat and ecology:— Known thus far only from the type locality in the montane forest remnants at the Sambotambo-Birón area, between 1300–1400 m, in El Oro province, south-western Ecuador ( Fig. 3 ). Three records from this population have been recorded by the Jocotoco park rangers on iNaturalist (https://www.inaturalist. org/observations/215750083, https://www.inaturalist.org/observations/215747630, https://www.inaturalist.org/ observations/203139819). According to the Ministerio del Ambiente del Ecuador (2013) this area lies in the Catamayo- Alamor evergreen piedmont forest (BsPn02) that harbors high diversity and endemism ( Cerón et al. 1999; Myers et al. 2000) as a result of the Andes and Tumbesian region influence. Field observations indicate that B. jocotocoi typically grows in humid and shaded microhabitats and co-occurs with the following species: Annona sp. ( Annonaceae ), Ceroxylon echinulatum ( Arecaceae ), Chusquea sp. ( Poaceae ), Pilea sp. ( Urticaceae ) and many bryophytes that cover the ground and branches of the trees and shrubs; moreover, the narrow endemic Magnolia buenaventurensis Á.J.Pérez & E.Rea (2023: 120) was recently described from the same locality.Additionally, this new species grows sympatrically with Begonia acerifolia Kunth (1825: 186) , B. piurensis L.B.Sm. & B.G.Schub. (1941: 197) and another new Begonia species that is in the process of being described.

Phenology:— Flowering from May to July and probably fruiting in August to October. Field observations suggest that this species is deciduous, and sheds its leaves between December and March, coinciding with the end of the dry season and the beginning of the rainy season.

Conservation status:— Known only from a single herbarium collection made from a population of around 10 individuals that we observed growing at the edge of a forest remnant in the Buenaventura Reserve , located close to the road in the Sambotambo-Birón area . Based on the available information and according to the IUCN Red List Criteria and Guidelines ( IUCN 2024), Begonia jocotocoi is preliminarily assessed as critically endangered ( CR B2 ab(iii)) based on a limited area of occupancy ( AOO <5 km 2) and a single known population, consisting of around 10 individuals ; additionally, mining and farming activities threaten the forest remnants around the type locality. In situ and ex situ propagation programs are urgently needed for this potentially ornamental species.

Notes:— Begonia jocotocoi belongs to sect. Knesebeckia , characterized by being a caulescent species with four tepals on the staminate flower, five tepals on the pistillate flower, and divided placentae ( Moonlight et al. 2018, 2023).

Figures

FIGURE 1. Begonia jocotocoi. A. Habit. B. Stem with stipules. C. Stipules. D.Adaxial leaf surface. E. Abaxial leaf surface. F. Trichomes on the petiole. From Pérez et al. 11782. Photographs by Álvaro J. Pérez.

FIGURE 2. Begonia jocotocoi. A. Lateral view of leaves and petioles. B. Inflorescence. C. Inflorescence, showing peduncle, pedicels, bracts and bracteoles. D. Staminate flower. E. Pistillate flower. From Pérez et al. 11782. Photographs by Álvaro J. Pérez.

FIGURE 3. Map of Ecuador, with insert showing the occurrence of Begonia jocotocoi (red dot) in El Oro province, Ecuador, in relation to local protected areas which are indicated by green shading and the Andean cordilleras indicated by grey shading.