Begonia tripicoensis E.L. Jacques, 2018

Jacques, Eliane De Lima, 2018, Four New Brazilian species of Begonia (Begoniaceae), Phytotaxa 381 (1), pp. 86-94 : 93

Begonia tripicoensis E.L. Jacques sp. nov. ( Figs. 1. G–O , 4. A–F )

Begonia tripicoensis is most similar to B. bidentata Raddi although it can be distinguished by having leaf blades with margins serratedenticulate (vs. bi-dentate), larger, pubescent stipules (1.3–2.4 cm long vs. 0.4–0,9 (–1.3) cm long, glabrous) and round capsules (vs. obovate). Type:— BRAZIL. Rio de Janeiro: Cachoeiras de Macacu, Parque Estadual de Três Picos, trilha da travessia Santo Amaro – São Lourenço, 779 m, 22°23´20.6” S, 42°42´17.4” W, 14 November 2011, E.L. Jacques, J. Wesenberg & I. Jacques 1788 (holotype RBR!, isotype RB!).

Description:—Subshrubs erect, terrestrial or rupicolous, ombrophilous, ca. 0.7–1.3 m tall, cystoliths present, best seen in hyaline structures; branches, petioles, stipules, veins on the abaxial surface of the leaf blades and peduncles pubescent, trichomes simple, with broad bases. Stems cylindrical, internodes 1.5–3 cm long. Leaves simple, petioles cylindrical, pubescent along their entire length, 0.1–0.5 cm long, stipules caducous, elliptic, light-green, membranaceous, 1.3–2.4 × 0.4 cm, adaxial surface glabrous, abaxial surface pubescent along the principal vein, margins slightly undulating, apex long-aristate, base asymmetrical; blades obovate to elliptic-obovate, slightly bifacial, chartaceous, 7.3–10.5 (– 11.5) × 3–4.5 cm, adaxial surface glabrous, abaxial surface pubescent along the principal and secondary veins, margins serrate–denticulate, teeth on the apex terminating in a hydathode, better seen on the adaxial surface of the blade, apex acuminate, base obtuse, slightly asymmetrical, venation craspedodromous, veins little evident. Inflorescence (3,5–) 5.5–7 cm long (including the rachis), rachis pilose, (1.7–) 3–3.5 cm long. Male flowers ca. 7 mm long, pedicel ca. 4 mm long, pubescent; tepals 4, white, all tepals reflexed at anthesis, external pair cochlear, broadly obovate, 5–7 × 3.5–4.5 mm, pilose, trichomes white, internal pair obovate, 2.5–3.5 × 1–1.5 mm, glabrous, stamens 20–27, connate, androphore ca. 0.5 mm long, anthers rimose, extrorse, obovoid, yellow, ca. 1 mm long, connective not prominent. Female flowers 1–1.5 mm long, pedicel pink, puberulous, 6–7 mm long, bracteoles 2, ca. 2 × 0.02 mm, at the base of the hypanthium, vinaceous to greenish-purple, tepals 5, white, 8–10 × 2.5–4 mm, puberulous on the lower third, margins lobed at apex, ovary 3–locular, stigmas 3, branches spiraled, greenish-white, 2–3 mm long, hypanthium white, ca. 3.5 mm long, puberulous, trichomes vinaceous, wings greenish-white, placentae entire. Capsules round, lateraloblong, 7–9 × 9–12 mm, glabrous, peduncles 8–9 mm long, puberulous, wings subequal, locular region elliptic, seeds brown, oblong, ca. 404 μm long.

Etymology:—The specific epithet refers to the type locality, the Três Picos State Park (Parque Estadual dos Três Picos). Approximately 1/2 of the conservation area lies within the municipality of Cachoeiras de Macacu, while the rest of the area is divided between the municipalities of Nova Friburgo, Teresópolis, Silva Jardim, and Guapimirim – all within Rio de Janeiro State, Brazil.

Phenology: —Flowering and fruiting in November.

Distribution and ecology: —Terrestrial plants, occasionally rupicolous, forming large populations on hillsides in shaded environments.The new species was observed growing next to Begonia arborescens Raddi , B. dentatiloba A.DC. , and B. integerrima Spreng. , as well as Geonoma cf. polianna Mart. , Sloanea sp , Besleria sp , Piper macrophyllum Sw. and pteridophytes, such as Dyplazium sp, Tectaria sp , and Cyathea sp. Begonia tripicoensis occurs in Dense Montane Ombrophilous Forests, at elevations near 780 m.

Additional specimens examined (paratypes):— BRAZIL. Rio de Janeiro: Cachoeiras de Macacu, Parque Estadual de Três Picos , 22°23´21”S, 42°42`26”W, 05 April 2010, R. A. Engelmann & O. Thier 652 ( LZ!, RB!, RBR!), ib., 05 April 2010, R. A. Engelmann & O. Thier 654 ( RB!) ; trilha entre Santo Amaro (Cachoeiras de Macacu) e São Lourenço (Nova Friburgo), próximo ao rio Santo Amaro , 22º23´29.4”S, 42º42´26.6”W, 14 November 2011, E. L. Jacques, J. Wensenberg & I. Jacques 1787 ( RBR!) ; ib., 22º23´21,1”S, 42º42´25,9”W, 14 November 2011, E. L. Jacques, J. Wensenberg & I. Jacques 1793 ( RBR!) .

Taxonomic notes:— Begonia tripicoensis can be easily recognized by having internodes pubescent, stipules caducous, 20–24 mm long, pubescent, petioles very short, 0.1–0.5 cm, blades 7.3–10.5(–11.5) × 3–4.5 cm, with leaf margins serrate–denticulate, apex acuminate, principal and secondary veins on the adaxial surface little evident, pubescent on the abaxial surface, capsules round, 7–9 mm long. The new species is similar to B. dentatiloba and B. bidentata , and can sometimes grow very near to them. Begonia tripicoensis , however, is easily distinguished from B. dentatiloba as the latter is a more robust plant, with stipules persistent, blades larger, 12–12.5 cm long, principal and secondary veins on the adaxial surface evident, prominent, and capsules larger (10–13 mm long), oblong. Begonia bidentata has internodes puberulous to glabrescent, stipules smaller (0.4–0.9(–1.3) cm long), glabrous, blades with margins bi-dentate, principal and secondary veins evident, deep, and capsules larger (ca. 13 mm long), obovate, with apex truncate.

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 4. A–F. Begonia tripicoensis E.L. Jacques. A, Habit; B, Flowering branch; C, Male flowers and female flower buds D, Female flowers E, Immature capsules; F, Capsules (A–B, F from Jacques 1787; C–E from Jacques 1788). Photos J. Wesenberg.