Solanum fernandesii V.S. Sampaio & R. Moura, 2016

Sampaio, Valéria Da Silva, Moura, Ricardo Loyola De & Loiola, Maria Iracema Bezerra, 2016, Solanum fernandesii (Solanaceae): A new species of ‘ spiny solanum’ of the Gardneri clade from northeastern Brazil, Phytotaxa 270 (1), pp. 33-40 : 34-39

Solanum fernandesii V.S. Sampaio & R. Moura , sp. nov. ( Figs. 1 , 2 )

Solanum fernandesii V.S. Sampaio & R. Moura is most similar to Solanum agrarium from which it differs by its small herbaceous to subshrub habit of 15–30 cm (vs. shrubs to 0.5 m tall.), with conical and slightly recurved spines (vs. acicular spines), hirsute indumentum (vs. glabrescent), presence of nectaries on the petiole (vs. absence), leaf blades with serrate margins (vs. entire to lobed blades), perfect flowers (vs. perfect and staminate flowers), calyx lobes in fruit triangular (vs. calyx lobes in fruit narrowly triangular) and suborbiculate winged seeds (vs. subreniform, not winged).

Type:–– BRAZIL. Ceará: Fortaleza, Campus do Pici, UFC, canteiro central, próximo ao Departamento de Biologia, 3º43’02”S, 38º32’35”W, 20 m, 27 February 2015 (fl, fr), V. S. Sampaio & R. L. Moura 132 (holotype: EAC! [ EAC 0057822], isotypes: BHCB!, JPB!, NY!, RB!).

Plant herbaceous to subshrub, erect or prostrate, aculeate, ca. 15–30 cm tall; stems terete, greenish to vinaceous, young stems moderately to densely hirsute, with glandular or simple hyaline uniseriate trichomes of 3–5 cells, older stems glabrescent, spines 1–4 mm long, conical and slightly recurved. Simpodial unit mostly trifoliate, rarely bifoliate. Leaves simple, petiole 0.3–2.5 cm long, decurrent, pubescent, with glandular or simple uniseriate trichomes, spines 1–5 mm long, conical and acicular, with a nectary at 1/5 from the petiole base; blade 1.5–6 × 0.8–3.5 cm, oval, concolor, apex rounded, acute, or truncate, base truncate or asymmetrical, membranaceous, margins serrate, venation craspedodromous, with 6–8 pairs of secondary veins, adaxial surface pubescent to glabrescent, trichomes glandular or simple, uniseriate of 3–5 cells, rarely porrect-stellate, abaxial surface glabrescent, with glandular and porrect-stellate sessile trichomes of similar size, with 3–4 radial cells and one central cell, spines 1–5 mm long, acicular. Inflorescences lateral, leaf-opposing, simple monocasial cyme, bearing 1–2 flowers; peduncle sessile or sub-sessile, ≤ 1 mm long, pedicel 5–25 mm long, pubescent, with glandular and rare simple uniseriate trichomes, unarmed or aculeate, spines acicular, 1–2 mm long; flowers perfect, pentamerous, monoclinous, buds oblong, calyx 2.5–6 mm diam., campanulate, tube 0.5–1.8 mm long, lobes 0.8–2 × 1.2–1.8 mm, triangular, straight at anthesis, aculeate, spines 0.5–1 mm long, acicular, corolla 1.5–2 cm diam., stellate, white, tube ≤ 1 mm long, lobes 7–9 mm long, lanceolate, with acute apex, planar or reflexed; stamens with filaments 1.8–2 mm long, anthers 4–6 × 1.1–1.2 mm, lanceolate, green or yellow, ovary 1.5 × 1.2–1.8 mm, pubescent, with glandular trichomes, style 5–8 mm long, cylindrical, light green to white, extending beyond anthers, stigma clavate, greenish. Fruit a berry 0.8–1.5 cm diam., ovoid to globose, epicarp variegated green when immature, vinaceous at maturity, glabrous, pedicel 1.8–3 cm long, deflexed, calyx 0.7–1.2 cm diam., not accrescent on the fruit, lobes vinaceous when young and paleaceous at maturity, glabrescent, with glandular and porrect-stellate sessile trichomes of similar size, with 3–4 radial cells and one central cell, aculeate, spines 1–1.5 mm long, conical. Seeds ca. 45–72, 3.8–6.5 × 3–5 mm, suborbicular, winged, compressed, beige.

Etymology: ––The specific epithet honors the Afrânio Fernandes, renowned botanist of Ceará, who has contributed about one fifth of the current holdings of EAC through his collecting efforts.

Distribution and habitat: –– Solanum fernandesii is a ruderal species of the states of Alagoas, Bahia, and Ceará of northeastern Brazil ( Fig. 3 ). It is found in open anthropogenically disturbed areas on coastal plains (tabuleiros) and in the caatinga biome, from sea level to 900 m of altitude.

Conservation status: ––Several criteria, such as the extent of its occurrence (EOO= 334,900 km 2), presence in open anthropic environments, with no records for protected areas, suggest its characterization as that of Least Concern (LC) ( IUCN 2014). Solanum fernandesii is a species of open and disturbed habitats, as are many ‘spiny solanum’ species.

Phenology: ––Individuals in flower and fruit were found from January to May, and August, with the flowering and fruiting peak for the first half of the year. Populations observed at the Campus do Pici, UFC, in Fortaleza, Ceará, were in flower one month after germination and with cotyledons in some individuals still present. Bees of the genus Plebeia have been observed visiting its flowers. Petals have been observed reflexed and planar in the morning, closing in late afternoons and evenings. Mature fruit has thin epicarp, and paleaceous calyx. Seeds are dispersed by ants.

Discussion: –– Solanum fernandesii is a member of the Gardneri clade. Morphologically, the species is close to S. agrarium , from which it differs by its smaller herbaceous habit, leaves with serrated margins and with a nectary at the petiole base, perfect flowers, and calyx lobes in fruit triangular, and suborbicular, winged seeds; whereas S. agrarium is a shrub, entire to lobed leaves, without nectaries, perfect and staminate flowers, with calyx lobes in fruit narrowly triangular, and subreniform non-winged seeds. Morphological differences between these two species are presented in Table 1.

With respect to the morphology of their foliar trichomes Solanum fernandesii has simple uniseriate 3–5-cellular trichomes and glandular trichomes of the multicellular uniseriate pedicel with a clavate head on the adaxial leaf surface, and porrect-stellate sessile trichomes of 3–4 radial cells and one central cell and glandular trichomes of the multicellular uniseriate pedicel with a clavate head on the abaxial surface. In contrast S. agrarium has simple uniseriate 2–3-cellular trichomes and glandular trichomes of the unicellular pedicel with a clavate head on the adaxial surface, and porrect-stellate sessile trichomes of 3–4 radial cells and one central cell and glandular trichomes of the unicellular pedicel with a clavate head on the abaxial surface ( Fig.4 ).

Both species have been recorded from northeastern Brazil, however, Solanum fernandesii is restricted to it, with records for the coastal planes (tabuleiros) and the caatinga biome limited to the states of Alagoas, Bahia, and Ceará. In contrast S. agrarium is a species widely distributed in the Neotropics and found in warm, dry areas of Colombia, Venezuela, the Caribbean and with a disjunct distribution in Brazil. In Brazil it is frequently found in pastures, along roadsides and abandoned land, on clay and sandy soils, at elevations from the sea level to over 1000 m, in the coastal areas and in the caatinga biome ( Agra et al. 2009; Solanaceae Source 2016 , http://www.solanaceaesource.org).

Additional specimens examined (paratypes): –– BRAZIL. Alagoas: Mun. Maceió, Campus UFAL, 17 February 2011 (fl, fr), Chagas-Mota 10204 ( MAC) . Bahia: Mun. Antônio Gonçalves, 10º36’16”S, 40º16’14”W, Caatinga (Savana estépica arborizada), 490 m, 12 April 2009 (fl, fr), E. Melo et al. 4426 ( HUEFS). Mun. Caetité, Região de Brejinhos das Ametistas, área da Bahia Mineração , 14º22’18”S, 42º32’25”W, 890 m, August 2008 (fr), M. S. Mendes et al. 650 ( HUEFS, BHCB). Mun. Feira de Santana , Campus da UEFS, 12º15’S, 38º58’W, 27 August 1983 (fl), L. R. Noblick 2723 ( HUEFS) ; Campus da Universidade Estadual de Feira de Santana , entorno do LABIO, 12º11’54”S, 38º56’6’’W, vegetação perturbada, 230 m, 24 March 2006 (fl, fr), J. G. Jardim 4980 ( HUEFS) ; Campus da UEFS, em frente ao LABIO, 12º15’S, 38º58’W, 4 May 2006 (fl, fr), L. P. Queiroz 12185 ( HUEFS) ; Mun. Rio de Contas, Estrada para a Fazenda Marion de Rio de Contas , 13º37’13”S, 41º45’54”W, área pertubada na beira da estrada, 895 m, 7 February 2004 (fl, fr), R. M. Harley et al. 54841 ( HUEFS) . Ceará: Mun. Fortaleza, Campus do Pici , 3º43’02”S, 38º32’35”W, 20 m, 27 August 2014 (fl, fr), V. S. Sampaio & R. L. Moura 127 ( EAC) ; 23 January 2015 (fl, fr), V. S. Sampaio & R. L. Moura 128 ( EAC) ; 2 February 2015 (fl, fr), V. S. Sampaio 129 ( EAC) ; 3 February 2015 (fl, fr), V. S. Sampaio 130 ( EAC) ; 1 April 2015 (fl, fr), V. S. Sampaio 142 ( EAC) .

Figures

FIGURE 1. Solanum fernandesii V.S. Sampaio & R. Moura. A. Flowering and fruiting branch. B. Flower at anthesis, with planar lobes. C. Flower with slightly reflexed lobes. D. Nectary on the petíole. E. Fruit. F. Seed. A–F (from V.S. Sampaio & R.L. Moura 132 EAC 0057822). Ilustration: Guilherme Rodrigues.

FIGURE 2. Solanum fernandesii V.S. Sampaio & R. Moura. A. Habit. B. Flowering branch. C. Petiole, with a nectary. D. Flower, with planar lobes, visited by a pollinator. E. Flower, with reflexed lobes. F. Flower, calyx lobes. G. Fruit, with deflexed pedicel. Photographs: A (R.S. Fonseca), B–C (V.S. Sampaio), D–F (R. Moura), G (R.S. Fonseca).

FIGURE 3. Geographic distribution of Solanum fernandesii.

FIGURE 4. Scanning electron micrographs of leaf epidermal surfaces. A–C. Solanum fernandesii (EAC 0057182): A. Adaxial surface with simple and multicellular glandular trichomes; B–C.Abaxial surface with sessile porrect-stellate and multicelular glandular trichomes. D–F. S. agrarium (EAC 0057844): D.Adaxial surface with simples and unicellular glandular trichomes; E–F.Abaxial surface with sessile porrect-stellate and unicellular glandular trichomes.