Solanum evolvuloides, Giacomin & Stehmann,

Stern, Stephen, Bohs, Lynn, Giacomin, Leandro, Stehmann, João & Knapp, Sandra, 2013, A Revision of Solanum Section Gonatotrichum, Systematic Botany 38 (2), pp. 470-496 : 483

3. SOLANUM EVOLVULOIDES Giacomin & Stehmann,

PhytoKeys 7: 1–9. 2011.

—TYPE: BRAZIL. Bahia: Mun. Jequié, Dist. Cachoeirinhas , caatinga arbustiva em topo de morro, com lajeados graníticos, 13 ° 54 ' 14.4 '' S, 40 ° 01 ' 46.8 '' W, 299 m, 10 Jul 2009 (fr), L.L. Giacomin 974 (holotype, BHCB!; isotypes to be distributed to BM, MBM, NY, RB).

Herb, slightly woody to woody at base, few- to manybranched, 2–4 dm tall. Stems moderately to densely pubescent with multicelled unbranched erect glandular hairs, these mixed with less frequent slightly longer 1–3-celled unbranched straight hairs. Sympodia 2-foliate, solitary or more commonly geminate, unequal with the smaller leaves up to half of the size of the larger ones. Leaf blades 1–4 + 1–3 cm, elliptic-ovoid to cordiform, chartaceous to membranaceous, sparsely to moderately pubescent adaxially and abaxially with 1 or 2-celled unbranched hairs, these denser along veins; base attenuate to cordate, often decurrent into petiole; apex acute; petioles 0.5–2.2 cm, moderately pubescent with hairs like those of the stem but with fewer eglandular hairs. Inflorescences with 1–4 flowers, the axes moderately pubescent with hairs like those of the stem; peduncles absent; rachis nearly absent; pedicels 6–10 mm in flower, 7–14 mm in fruit. Flowers with the calyx 2–7 mm long, the tube 1–2 mm, the lobes 2–6 + 1–2.6 mm, ovate-elliptic, the apex acuminate, moderately pubescent abaxially with almost exclusively glandular unbranched multicellular erect hairs; fruiting calyx accrescent, the lobes up to 8 mm long, equal to or exceeding the berry at maturity. Corolla 1–3 cm in diameter, rotate with abundant interpetalar tissue, membranaceous, white, the tube 4–6 mm, the lobes 2–4 + 1–3 mm, triangular, acute at apices, with a few eglandular hairs abaxially, mainly on the central part of each lobe, glabrous adaxially. Stamens 4–9.5 mm long; upper, shorter filaments 1–2 mm, the lowermost, longer filament 3–7 mm; anthers 4–6 + 1.3–2 mm, oblong, the base cordate, with a small bulge dorsally, the apex emarginate, the pores directed introrsely and subapically, not opening into longitudinal slits. Ovary glabrous; style 7–9 + 0.5–1 mm, longer than the smaller stamens, closely appressed to the larger stamen, curved near apex: stigma to 1 mm wide. Berries 8–15 mm in diameter, globose, greenish-white when immature, maturing translucent, drying brown to blackish, glabrous, the mesocarp watery and held under pressure until dehiscing explosively at maturity, normally between two calyx lobes. Seeds 10–25 per fruit, 2.5–3.6 + 1.8–2.9 mm, reniform, with a small hollow where connected to the placenta, the margin flattened, the seed surface with raised projections and grooves parallel to margin, giving a netlike impression. Figure 8 .

Habitat and Distribution— An herb of the transition zone between deciduous forests and xeric formations of shrubby caatinga. It is known only from a restricted area in the southeastern part of Bahia State, Brazil at 0– 275 m in elevation ( Fig. 5 ).

Phenology— Flowering and fruiting materials were collected between February and August, with a flowering peak from February to May; fruiting specimens were collected from June to August.

Conservation Status— The IUCN Red List Status of S. evolvuloides is Endangered based on an area of occupancy <5000 km 2, <5 collection localities and declines in extent of occurrence, area of occupancy, quality of habitat, and number of locations. The species is known from only two localities where the landscape has been strongly modified in the last decades due to the expansion of urban centers and extensive farming. The region has been the focus of several surveys undertaken by the Centro de Pesquisas do Cacau in association with the New York Botanical Garden; despite this, just a few collections of this species have been made. Although one collection was made in a disturbed area (Jardim 1843), the most recent collection is from a well-preserved forest fragment, and the species was not found in surrounding areas. There are no collections from within conservation units.

Etymology— The epithet is derived from the similar leaf shape and habit shared with members of the genus Evolvulus L. of the Convolvulaceae.

Additional Specimens Examined— BRAZIL. Bahia: Km 7 da estrada Jequié/Ipiaú, caatinga, 10 Feb 1983 (fl), Carvalho 1591 (CEPEC); Mun. Itacaré, Fazenda Monte Alegre, ca. 1 km a leste na rodovia para Itacaré, margem do Rio de Contas, 10 Aug 1998 (fl, fr), Jardim 1843 (CEPEC); Mun. Jequié, Rodovia Ipiaú/Jequié, 12 May 1969 (fl, fr), Jesus 367 (CEPEC); Mun. de Manoel Vitorino, Rod. Man. Vitorino/ Caatingal, Km 4, região de caatinga, 16 February 1979 (fl, fr), Mattos Silva s.n. (CEPEC).

Notes— The species is closely related to S. turneroides and shares with it notable heteranthery, with the filament of one stamen much longer than the other four. Like S. turneroides , the flowers are only open in the morning and close by midday. Solanum evolvuloides can be easily distinguished from all other species in sect. Gonatotrichum by the glandular, multicellular hairs on the stems, inflorescences, and flowers that are not found in any other species of the section.

Jardim 1843 from the banks of the Rio de Contas near the city of Itacaré might be an occasional case of water dispersal by the Contas River, which originates in a xeric environment near the center of Bahia in the caatinga biome.

Figures

FIG. 8. Photos of type collection of S. evolvuloides (Giacomin 974, BHCB). A. Habit. B. Flower; note glandular hairs on calyx. C. Flower; note the elongated lowermost stamen. D. Flower. E. Fruit; note the thin, nearly transparent skin. Scale bars: A = 2 cm. B = 5 mm. C, D, E = 1 cm.

FIG. 5. Distribution of S. adscendens, S. evolvuloides, S. hoffmanseggii, S. olympicum, and S. turneroides.