Besleria diabolica G.E.Ferreira & Chautems, 2016

Ferreira, Gabriel E., Costa, Idimá G., Araujo, Andréa O., Hopkins, Michael G. & Chautems, Alain, 2016, Three new species of Besleria (Gesneriaceae) from the southeastern Brazilian Atlantic rainforest, Phytotaxa 263 (3), pp. 270-278 : 275-277

Besleria diabolica G.E.Ferreira & Chautems , sp. nov. ( Fig. 3 )

Besleria diabolica is similar to B. melancholica in having flowers with reflexed, flat calyx lobes. However, B. diabolica differs by its longer leaf blades, usually fewer flowers per axil and by its narrower, lanceolate calyx lobes, with acute apices.

Type:— BRAZIL. São Paulo: Eldorado, Parque Estadual Caverna do Diabo, trilha do Araçá , nas margens do córrego, 29 September 2014, G. E. Ferreira et al. 271 (holotype INPA!; isotypes G!; HUFABC!; SPSF!) .

Terrestrial shrub, 0.8–1.5 m tall. Stems unbranched, subterete, 0.4–0.5 cm diam., green, hirsute, internodes 1.3–3.2 cm long. Leaves opposite and decussate, pairs subequal; petioles 3.2–5.5 cm long, green, hirsute; leaf blades elliptic to lanceolate, 16.0–22.5 × 3.2–6.0 cm, apex and base attenuate, margin distantly denticulate and ciliate, membranaceous; adaxial surface green, hirsute; abaxial surface pale green, hirsute, 6–9 pairs of secondary veins. Inflorescence axillary, cymose, epedunculate or rarely with a very short peduncle, with 1–3 flowers per node; pedicels terete, 1.2–1.7 cm long, green, hirsute. Calyx lobes 5, fused and imbricate at base, spreading, subequal, lanceolate, 1.0–1.4 × 0.3–0.4 cm, apex attenuate, margin entire, yellow, hirsute. Corolla oblique in relation to calyx, 18–24 mm long, tube contracted at base, limb regular, 6 mm wide at the base, 5 mm wide at the narrowest point, throat 7 mm wide, ventricose, yellowish-white, glabrous outside and inside; lobes 5, reflexed, slightly equal, semiorbicular, 2 × 4 mm, margin entire, white, glabrous. Nectary annular, 0.5 mm wide, glabrous. Stamens 4, included in the throat; filaments 5–6 mm, epipetalous, adnate, free portion of filaments arising in the middle of the corolla tube, glabrous; anthers 1 × 2 mm, longitudinally dehiscent; staminode 0.4 cm long. Ovary ovoid, 4 × 5 mm, glabrous; style included in the throat, 11–15 mm long, glabrous; stigma bifid. Fruit not seen.

Distribution and ecology:— Besleria diabolica is known from Eldorado and Miracatú, municipalities in the southern part of São Paulo state ( Fig. 5 ). The vegetation type in this region is Atlantic rainforest of the Atlantic forest domain. The species usually occurs along banks of streams within forested areas at around 400 m elevation. Based on our own observations in the vicinity of the “Caverna do Diabo” state park only a few scattered individuals were seen, indicating a low population density.

Phenology:— Flowers are recorded from September to November.

Conservation status:— Endangered (EN) B1ab(i,iv), according to the IUCN criteria, based on the extent of occurrence estimated to be less than 5,000 km 2 in only two locations ( IUCN 2013).

Taxonomic relationships:— This new species is somewhat similar to Besleria melancholica ( Vellozo 1825: 260) Morton (1939: 446) in the shape and position of the calyx lobes, but it can be differentiated by the narrower calyx lobes (3–4 mm vs. 4–7 mm wide), which are lanceolate with acute apices (vs. oblong with obtuse apices). Inflorescences of B. melancholica may have many flowers, 5–6 (more commonly 2–4), while B. diabolica has 1–3 flowers per inflorescence ( Fig. 4G ). Geographically, B. diabolica has a different distribution occurring only in southern São Paulo state, whereas B. melancholica is restricted to mountainous areas in Rio de Janeiro state.

Etymology: — The name “diabolica ” is a reference to the first place where this species was found, around the “Caverna do Diabo” state park, which is located in the southern region of São Paulo state in Brazil.

Additional specimens examined (paratypes):— BRAZIL. São Paulo: Eldorado, nas proximidades da Caverna do Diabo , 11 November 2000, E. R. Salviani & H. Lorenzi 1773 ( HPL!, INPA!) ; Miracatú, perto de Pedro Barros, 30 Ago 1966, J. Mattos s.n. ( RB!) .

Figures

FIGURE 3. Besleria diabolica. A. Corolla opened to show stamens and staminode. B. Pistil and nectary. C. Calyx without corolla in lateral view. D. Calyx and corolla in frontal view. E. Habit (A–D from E.R. Salviani & H. Lorenzi 1773 and E from G.E. Ferreira et al. 271).

FIGURE 4. Morphology and habitat of the new species of Besleria. A–B. Besleria aurea. A. Calyx and corolla in frontal view. B. Calyx and corolla in lateral view. C–D. Besleria brevicalyx. C. Calyx and corolla in frontal view. D. Habit and habitat. E–G. Besleria diabolica. E. Flowering branch. F. Habit. G. Calyx in lateral view. (A–B from I.G. Costa 230; C–D from G.E. Ferreira et al. 292; E from T. Flores s.n., F–G from G.E. Ferreira et al. 271).

FIGURE 5. Distribution of the three new species of Besleria in eastern of Brazil.