Besleria iara G. E. Ferreira & M. J. G. Hopkins, 2017

Gabriel Emiliano Ferreira, Andréa Onofre De Araújo, Michael John Gilbert Hopkins & Alain Chautems, 2017, A new species of Besleria (Gesneriaceae) from the western Amazon rainforest, Brittonia 69 (2), pp. 241-245 : 241-245

Besleria iara G. E. Ferreira & M. J. G. Hopkins , sp. nov.

Type: Brazil. Amazonas: Benjamin Constant , sítio Prof. Agno Nonato, trilha prox. ao açude, 8 February 2016, G. E. Ferreira 355 (holotype: INPA; isotype: G). ( Figs. 1 , 2 )

Besleria iara is similar to B. aggregata s.l. in its axillary inflorescences, and flowers with orange imbricate calyx lobes. It differs by having a long tubular-ventricose yellow corolla (vs. ventricose-urceolate orange to scarlet), and larger leaf blades, 18– 30 × 7.3–11.4 cm, with serrate margins (vs. 15–19 × 5.5–6.4 cm, with entire margins).

Terrestrial shrub, 1.5 m tall. Stems unbranched, subterete, up to 0.5 cm diam., woody at base, densely hirsute, internodes 3.0–11.0 cm. Leaves opposite, pairs subequal; petioles 1–4 cm long, green, densely hirsute; leaf blades oblanceolate, 18–30 × 7.3–11.4 cm, chartaceous, apex attenuate, base long-attenuate, margin sparsely serrate; adaxial surface dark green, hirsute; abaxial surface pale green, puberulous; secondary veins in 7–1 1 pairs. Inflorescence axillary, cymose, epedunculate, with 3–7 flowers per node; pedicels terete, 1.2–2.3 cm long, orangish, hirsute. Calyx lobes 5, fused at base and imbricate for 3/4 of length, adherent to corolla base, essentially equal, ovate, 12–14 × 3–5 mm, orange, hirsute, apex obtuse, margin entire-ciliate. Corolla erect with respect to calyx , 18–27 mm long, tubular, slightly ventricose, yellow, outside puberulous, inside glabrous, tube contracted at base, 5 mm wide at base, 7 mm wide at middle, 5 mm wide at apex; limb regular, lobes 5, patent, yellow, unequal, the 2 larger ones 4 × 4 mm, the 3 smaller ones 2 × 3 mm, obtuse, margin entire, ciliate, pilose. Nectary annular, 1 mm wide, glabrous. Stamens 4, includ- ed; filaments 8–10 mm long, epipetal, adnate to base of corolla for 4 mm, glabrous but pilose at insertion; anthers 2 × 2 mm, longitudinally dehiscent; staminode 2 mm long. Ovary ovoid, 2–4 × 2–4 mm, pilose; style included within corolla throat, 9 mm long, pilose; stigma bifid, puberulent. Fruit not seen.

Habitat and distribution.— Besleria iara is currently known only from the Javari River, in the municipalities of Atalaia do Norte and Benjamin Constant, Amazonas, Brazil, and from Loreto department, Peru (Fig. 3). It occurs in the understory of lowland Amazonian rainforests on terra firme, along the margins of small streams, at about 50 m elevation. We observed few individuals at the type locality. The larger area of distribution is poorly known from a floristic context. It is expected that additional fieldwork in the region will result in the discovery of additional populations.

Phenology.— Flowers recorded from October to February.

Etymology.— The specific epithet B iara ^ is a reference to the Brazilian indigenous legend of the water spirit yîara, meaning BLady of the waters^ in the Tupí-Guaraní language. Yîara is generally envisaged as a beautiful young lady, similar to a mermaid ( Chiaradia, 2008).

Conservation status.— Endangered (EN) B1ab, according to the IUCN criteria, based on the extent of occurrence estimated to be less than 5,000 km 2 from only 4–5 locations and due to continued habitat loss ( IUCN, 2012; IUCN Standards and Petitions Subcommittee, 2016).

Additional specimens examined. BRAZIL. Amazonas: Município Atalaia do Norte, localidade de São Joaquim, Rio Javari, fronteira entre Brasil e Peru , 18 Jan 1989, C. A.C. Ferreira et al. 993 3 ( CEN, INPA, NY, US) ; Município Atalaia do Norte, Estirão do Equador, Rio Javari , 20 Oct 1976, P. I. S.

Braga & J. R. Nascimento 3273 ( INPA). PERU. Loreto: Rio Javari, 2 hours above Rio Javarizinho, 24 Oct 1976, G. T. Prance et al. 24081 ( INPA, MG).

Besleria iara and B. aggregata (Mart.) Hanst. are sympatric and share the same habitat and vegetative characters. Both species occur in the understory of humid forest, close to streams, and are shrubs completely covered by indumentum. However, B. iara has a yellow, tubular-ventricose corolla, ovate calyx lobes with the obtuse apices adherent to the corolla base, wider leaf blades (7.3–11.4 cm wide) with sparsely serrate margins, and densely hirsute indumentum on the stems, whereas B. aggregata has an orange to scarlet, ventricose-urceolate corolla, lanceolate calyx lobes with the attenuate apices spreading from the corolla, narrower leaf blades (5.5–6.4 cm wide) with entire margins, and sericeous indumentum on the stems (Table 1).

Besleria iara is also morphologically similar to B. obtusa C. V. Morton , known only from the type collection (J. Cuatrecasas 4636, Colombia, Meta, 1939). Both species have oblanceolate leaves and a yellow corolla, but B. iara can be distinguished from B. obtusa by having a longer petiole (1.0– 4.0 cm long vs. <1 cm long), hirsute leaf blades (vs. glabrous with tomentose-hirsute midrib), sparsely serrate margins (vs. entire-ciliate), longer pedicels (1.2–2.3 cm long vs. 0.5 cm long), ovate calyx lobes with the obtuse apices adherent to the corolla (vs. calyx lobes linear-lanceolate with the long-acuminate apices spreading).

Figures

FIG. 1. Besleria iara. A. Habit. B. Open Corolla showing stamens and staminode. C. Gynoecium and Nectary. D. Close up of the inflorescence and stem. E. Calyx and Corolla in side view. (A – E from G. E. Ferreira 355).

FIG. 2. Morphology and habitat of Besleria iara. A. Flowers in frontal and side view and a portion of the stem. B. Flower in side view. C. Habit. D. Inflorescence. E. Detail of the leaf abaxial surface (A – E from G. E. Ferreira 355).