Begonia itingae E.L. Jacques, 2018

Jacques, Eliane De Lima, 2018, Four New Brazilian species of Begonia (Begoniaceae), Phytotaxa 381 (1), pp. 86-94 : 86-87

Begonia itingae E.L. Jacques , sp. nov. ( Figs. 1 A–F ; 2 A–F )

Begonia itingae is most similar to B. organensis Brade but differs by having peltate leaves (vs. basifixed) and a larger membranous ring at the apex of the petiole (4–5 mm long vs. 1–2 mm).

Type:— BRASIL. Rio de Janeiro: Rio Claro, Serra do Sinfrônio, Parque Estadual do Cunhambebe, Trilha para a Pedra Chata, 22°53´58.5” S, 44°10´28.6” W, 1200 m, 11 June 2018, E. L. Jacques 2013, G. Guimarães & M. A. S. Santos (holotype RBR!, isotype RB!).

Description:—Subshrubs, erect, terrestrial, 0.7–1 m tall (excluding the inflorescence), glabrous. Cystoliths absent. Stem erect, internodes greenish, with brown tinges, 3.5–11 cm long, glabrous. Leaves simple, petioles semicylindrical in cross-section, 11–16 cm long, glabrous along their entire length, with a fleshy ring at the tip, margins dentate, internally with 2–5 fleshy projections, 13 mm in diameter, 4–5 mm long (10–11 mm long in living material), stipules persistent, ovate, fleshy, becoming scarious, 3–5 × 1.9–4.5 cm, apex obtuse, dorsally carinate, glabrous, blades peltate, entire, transversely ovate, 17–19.5 × 10–12.5 cm, adaxial surface glabrous except for two opposite and diminutive fleshy projections on the umbo, abaxial surface with diminutive scales sparsely distributed on the larger veins to glabrous, margins entire, apex acuminate, base peltate, veins 6–7. Inflorescence 4-branched cyme, up to ca. 45 cm tall when fruiting, rachis vinaceous (up to ca. 24.5 cm when fruiting). Male flowers ca. 30 mm long, pedicels 17–23 mm long, glabrous; tepals 4, white, external pair broadly elliptic, 25–30 × 25–28 mm, with scale-like trichomes on the external surface, internal pair obovate, 17–19 × 8–9 mm, glabrous, stamens 52, free, ca. 5 mm long, anthers ellipsoid, yellow, ca. 4 mm long, rimose, with frontal openings, extrorse, filaments ca. 1.5 mm long, connectives prominently projecting, ca. 0.2 mm long. Female flowers ca. 60 mm long, pedicel 10–17 mm long; bracteoles 2, caducous, located on the apex of pedicel, orbicular, 6–10 × 9–10 mm, with microscopic glandular trichomes; tepals 5, white, the external three larger, 2–2.7 × 1.3–1.9 mm, with scale-like trichomes on the external surface, ovary 3–locular, styles 3, ca. 6 mm long, hypanthium ca. 8 mm long, with a few microscopic glandular trichomes, and scale-like trichomes; placentae bilamellate, ovules on both faces of the lamellae. Capsules 15–18 × 40 mm (including the largest wing); pedicels 25–30 mm long, wings vinous, seminiferous nucleus 25 mm, green-vinaceous, with scale-like trichomes, largest wing 23–32 × 15–19 mm, two smaller wings inconspicuous; seeds oblong, 530–533 μm long.

Etymology:—The specific epithet refers to the municipality of Rio Claro, in its translation from the old Amerindian Tupi language “ Itinga” of the Tamoios tribe. They had a chief called Cunhambebe, whose name was given to the park where the holotype was encountered.

Phenology: —Flowering and fruiting between June and August.

Distribution and ecology: —The new species is endemic to Rio de Janeiro State where it grows on rocky slopes and outcrops within the Atlantic Forest. Is known only from the type locality, the Cunhambebe State Park (Parque Estadual do Cunhambebe) in the municipality of Rio Claro, in the southern region of Rio de Janeiro State, Brazil.

Additional specimens examined (paratypes):— BRAZIL. Rio de Janeiro: Rio Claro, Lídice, Parque Estadual do Cunhambebe , [Reserva Estadual do Cunhambebe], estrada para o Sinfrônio , 22°53´51”S, 44°13´14”W, 8 August 2013, D. S. P. Silva et al. 71 ( RB!) ; ib., 8 August 2013, D. S. P. Silva et al. 72 ( RB!) ; ib., trilha para a Pedra Chata , 22°53´56,6” S, 44°10´44,7” W, 1022 m, 11 June 2018, E. L. Jacques, G. Guimarães & M. A. S. Santos 2006 ( RBR!) .

Taxonomic notes:— By the presence of a membranous ring at the petiole apex, Begonia itingae resembles B. caraguatatubensis Brade (which is endemic to São Paulo State) as well as B. collaris Brade and B. organensis Brade (which are endemic to Rio de Janeiro State); for additional commentaries on B. collaris , refer to Jacques (1996). Begonia itingae is similar to B. organensis in having stipules that are large, scarious, and persistent, the abaxial surface of the leaf blade with sparse scale-like trichomes on the largest veins, placentae bilamellate, and similar fruits. Begonia organensis , however, has basifixed leaves (vs. peltate) and smaller membranous rings on the petiole apex 1–2 mm (vs. 4–5 mm). Begonia caraguatatubensis and B. collaris have caducous stipules, smaller capsules, with rounded wings and entire placentae.

Figures

FIGURE 1. A–F. Begonia itingae E.L. Jacques. A, Flowering plants; B, Portion of leaf showing a fleshy ring at the petiole apex; C, Male flower; D, Female flower; E, Female flower, stigma in detail; F, Capsule. G–O. Begonia tripicoensis E.L. Jacques. G, Habit; H, Leaf base; I, Trichome; J, Male flower bud; K, Male flower, stamens in detail; L, Male flower; M, Female flowers with bracteoles; N, Female flowers; O, Capsule. (A–F from Jacques 2013; G–O from Jacques 1788).

FIGURE 2. A–F. Begonia itingae E.L. Jacques. A, Habit of mature plant; B, Habit of young plant; C, Leaves; D, Leaves with a fleshy ring at the petiole apex; E, Infructescences; F, Fruits. (A–F from Jacques 2013; A= 20 cm; B= 5 cm; C= 2.5 cm; D= 1.3 cm; E= 1 cm; F= 0.5 cm). Photos M.C. Souza.