Two new non-spiny Solanum (Solanaceae) from the Gran Chaco Americano and a key for the herbaceous glandular-pubescent solanums from the region.

Tiina Särkinen,Sandra Knapp

doi:10.3897/phytokeys.74.10159

Abstract

The Gran Chaco Americano is a major savanna woodland system in South America that harbours great plant and animal diversity. Two new herbaceous species of the Morelloid clade of Solanum (largely corresponding to the traditional Solanum section Solanum) are described here from the Bolivian Chaco. Both species are morphologically similar to a group of related species with glandular pubescence and enlarged, foliaceous calyces that includes Solanum atriplicifolium Gillies ex Nees, Solanum nitidibaccatum Bitter, Solanum physalifolium Rusby, Solanum sarrachoides Sendtn. and Solanum tweedianum Hook. Solanum woodii Särkinen & S.Knapp, sp. nov. is unusual in the Morelloid clade in having tapering anthers on short filaments, and is superficially similar to the unrelated Solanum anomalostemon S.Knapp & M.Nee from dry forests in Peru. Solanum michaelis Särkinen & S.Knapp, sp. nov. is distinct in its enlarged calyx with a short tube and long lobes that apparently reflex at fruit maturity. Both new taxa are illustrated, their conservation status assessed, and their distributions mapped. We also provide a key to the glandular-pubescent herbaceous Solanum species of the Chaco vegetation to aid in identification of these taxa.

Highlights

Solanum L. is one of the most species-rich vascular plant genera in South America (Jørgensen et al 2011), where many new species continue to be described (e.g., Anderson et al 2006; Stern 2014; Stern and Bohs 2010; Knapp 2010 a,b; Farruggia and Bohs 2010; Tepe and Bohs 2009; Tepe et al 2012; Särkinen et al 2013a, 2015a, 2015b)
A total of six species of Solanum from the Morelloid clade are known to occur in the Chaco region, and we provide a key for the identification of similar glandular-pubescent herbaceous non-spiny solanums from the Gran Chaco Americano
Solanum physalifolium has similar shiny green-mottled berries, but occurs at higher elevations (1,400–2,900 m) in yungas or wet forest vegetation and has broadly ovate calyx lobes that partially enclose the fruit at maturity

Summary

Introduction

Solanum L. is one of the most species-rich vascular plant genera in South America (Jørgensen et al 2011), where many new species continue to be described (e.g., Anderson et al 2006; Stern 2014; Stern and Bohs 2010; Knapp 2010 a,b; Farruggia and Bohs 2010; Tepe and Bohs 2009; Tepe et al 2012; Särkinen et al 2013a, 2015a, 2015b). Within South America, the tropical Andes represent one of the main centres of species diversity for Solanum for both spiny (Leptostemonum clade, see Stern et al 2011) and non-spiny clades (Weese and Bohs 2007; Särkinen et al 2013b). Section Solanum is distinguished by its herbaceous or sub-shrubby habit, inflorescences usually positioned along the internodes, small flowers and fruits, and the usual possession of stone cells in the fruits (Bitter 1911), which appear as small, seed-like structures that are usually white and spherical rather than flattened and brown or yellowish brown like the seeds. A total of six species of Solanum from the Morelloid clade are known to occur in the Chaco region, and we provide a key for the identification of similar glandular-pubescent herbaceous non-spiny solanums from the Gran Chaco Americano

Materials and methods

Discussion

Findings