Solanum salamancae Hunz. & Barboza, Lorentzia 7: 17, fig. 1. 1993.

Knapp, Sandra, Saerkinen, Tiina & Barboza, Gloria E., 2023, A revision of the South American species of the Morelloid clade (Solanum L., Solanaceae), PhytoKeys 231, pp. 1-342 : 1

49. Solanum salamancae Hunz. & Barboza, Lorentzia 7: 17, fig. 1. 1993.

Figs 149 , 150

Type.

Argentina. Salta: Dpto. Guachipas: La Salamanca, viniendo desde San Carlos, rumbo a La Vina, La Salamanca, A.T. Hunziker & R. Subils 24049 (holotype: CORD [CORD00004293]; isotypes: CORD [CORD00004292], MA [ MA771370 ]) .

Description.

Annual herbs 0.2-0.7 m high, often spreading and sprawling. Stems somewhat winged or with prominent spinose processes from the remnant, stiffened bases of trichomes, sparsely to moderately pubescent with eglandular white 6-8-celled simple uniseriate trichomes 0.5-2(-3.5) mm long, these usually spreading and tangled, but sometimes antrorse (collections from Metán, Salta with extremely long trichomes); new growth sparsely to densely pubescent with eglandular, 6-8-celled simple uniseriate trichomes 0.5-2 mm long; bark of older stems pale yellow, glabrescent, but spinose processes persistent. Sympodial units difoliate, the leaves more or less geminate, if geminate then more or less equal in size and shape. Leaves simple, entire or somewhat toothed, the blades (3)3.5-11 cm long, 2-7 cm wide narrowly ovate to narrowly elliptic, widest in the lower third, membranous, concolorous; adaxial surfaces almost glabrous to sparsely pubescent with eglandular, simple uniseriate trichomes to 1 mm long, these mostly on the veins; abaxial surfaces similarly almost glabrous to sparsely pubescent, but the trichomes denser along the midvein; principal veins 6-7 pairs, usually sparsely pubescent with eglandular, white, simple uniseriate trichomes; base truncate-attenuate to attenuate and decurrent along the petiole; margins entire or irregularly and shallowly toothed in the lower third of the blade or along the entire margin, the teeth 1-3 mm long; apex acute to acuminate; petiole (0.5)1-1.5(-2.6) cm long including the winged portion of the leaf base, pubescent with eglandular white simple uniseriate trichomes like those of the leaf surfaces. Inflorescences internodal, arising just below the geminate leaf pair, unbranched, 1.5-7.5 cm long, with 5-10 flowers in the distal third, these somewhat secund, sparsely pubescent with spreading, eglandular, simple uniseriate trichomes to 2 mm long like those of the stems; peduncle 1-4 cm long; pedicels 0.7-1 cm long at anthesis, ca. 0.5 mm in diameter at the base, ca. 0.5 mm in diameter at the apex, filiform and slightly widening at the base of the calyx tube, secund to somewhat spreading at anthesis, sparsely pubescent with simple uniseriate trichomes like the rest of the inflorescence, articulated near the base, leaving a distinct stump; pedicel scars evenly spaced 1-1.5 mm apart. Buds narrowly ellipsoid to ellipsoid, the corolla strongly exserted from the calyx tube before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1-1.5 mm long, conical, the lobes 1.2-3 mm long, long-triangular with acuminate tips, sparsely pubescent with eglandular, white simple uniseriate trichomes to 2 mm long like the rest of the inflorescence. Corolla ca. 1.5 cm in diameter, white with a pale green central star, this sometimes with purple margins, stellate, lobed ca. halfway to the base, the lobes 4.5-5 mm long, 2-2.5 mm wide, spreading to somewhat reflexed at anthesis, adaxially glabrous, abaxially with scattered eglandular, simple uniseriate trichomes ca. 0.5 mm long on the tips and midvein. Stamens equal; filament tube 0.1-0.5 mm long; free portion of the filaments 1-1.5 mm long, pubescent with translucent tangled simple uniseriate trichomes abaxially; anthers 3.5-5 mm long, 1-1.2 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 6-7 mm long, straight, exserted beyond the anther cone, densely pubescent in the lower 2/3 (within the anther cone) with unicellular papillae and tangled unicellular trichomes; stigma large-capitate, green in live plants, the surface minutely papillate. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1-1.5 mm long, conical, the lobes 1.2-3 mm long, long-triangular with acuminate tips, sparsely pubescent with eglandular, white simple uniseriate trichomes to 2 mm long like the rest of the inflorescence. Corolla ca. 1.5 cm in diameter, white with a pale green central star, this sometimes with purple margins, stellate, lobed ca. halfway to the base, the lobes 4.5-5 mm long, 2-2.5 mm wide, spreading to somewhat reflexed at anthesis, adaxially glabrous, abaxially with scattered eglandular, simple uniseriate trichomes ca. 0.5 mm long on the tips and midvein. Stamens equal; filament tube 0.1-0.5 mm long; free portion of the filaments 1-1.5 mm long, pubescent with translucent tangled simple uniseriate trichomes abaxially; anthers 3.5-5 mm long, 1-1.2 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 6-7 mm long, straight, exserted beyond the anther cone, densely pubescent in the lower 2/3 (within the anther cone) with unicellular papillae and tangled unicellular trichomes; stigma large-capitate, green in live plants, the surface minutely papillate. Fruit a globose berry, 0.7-0.9 cm in diameter, green when mature, enclosed in the inflated calyx but the tip of the berry visible at fruit maturity, the pericarp thin, shiny, translucent, glabrous; fruiting pedicels 1.2-1.4 cm long, 0.5-0.7 mm in diameter at the base, strongly hooked at insertion point onto the inflorescence axis, 2-2.5 mm in diameter at the apex just below inflated calyx, not persistent; fruiting calyx accrescent and inflated, invaginate (saccate) at the base, the tube to 1 cm long, almost completely covering berry, the lobes ca. 3 mm long, ca. 3 mm wide, broadly triangular, apiculate. Seeds 20-40 per berry, 2-2.5 mm long, 1.5-2 m wide, flattened and teardrop shaped, brown or dark brown, the surfaces minutely pitted, the testal cells rectangular or slightly sinuate in outline. Stone cells 2-4 per berry, ca. 0.7 mm in diameter, cream-coloured. Chromosome number: not known.

Distribution

(Fig. 151 ). Solanum salamancae is endemic to Argentina (Provs. Catamarca, Salta, Tucumán).

Ecology and habitat.

Solanum salamancae grows in dry forests ("chaco serrano"), in the transition zone between forest and prepuna, often at seasonal stream margins in sandy soils or at field edges, from 1,200 to 3,000 m elevation.

Common names and uses. None recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 79,244 km2 [LC]; AOO = 84 km2 [EN]. Solanum salamancae occurs all along the Andean slope in northern Argentina and is a weedy species, but because it grows in a narrow, transitional habitat, future studies might reveal habitat specialisation. Many recent collections are from areas around active mining operations (e.g., Tolaba & Gutiérrez 4240) and so these populations may be at risk.

Discussion.

Solanum salamancae is a distinctive species with winged or strongly spinescent stems, lacking glandular pubescence and with accrescent, inflated calyces with invaginate bases that completely enclose the berry. Other taxa with similarly accrescent calyces ( S. hunzikeri , S. nitidibaccatum , S. physalidicalyx , S. sarrachoides , S. tweedieanum ) are densely viscid-glandular pubescent. The strongly inflated calyces of S. salamancae are most similar to those of S. physalidicalyx ; accrescent calyces of these similar species only partially cover the berry or are tightly appressed to it (e.g., S. tweedieanum ).

Populations of S. salamancae from the region of Metán (Prov. Salta) are consistently more long-pubescent than in other areas of the species range (e.g., Tolaba & Gutiérrez 4238 and others collected around the same area) and the trichomes are often strongly antrorse.

Figures

Figure 149. Solanum salamancae A habit B stem cross section C spinose process with an eglandular trichome D flower E dissected flower F forked trichome of the filament G gynoecium H eglandular trichome of the style I stigma J fruit K fruit cross section L stone cell M seed N seed cross section O detail of the episperm P embryo (A-P Hunziker & Subils 24049). Illustration by L. Sanchez. Previously published in Barboza et al. (2013: 257).

Figure 150. Solanum salamancae A habit B fruiting branch with developing fruits with large calyx lobes C fruiting branch with mature fruits D mature fruits inside inflated calyces (A Hunziker & Subils 24049 [MA 771370] B Novara & Bruno 9637 [S-R- 9196] C Novara & Bruno 9637 [CORD 00004294] D Hunziker & Subils 24049 [CORD 00004292]). Reproduced with permission of the Real Jardin Botanico de Madrid, Swedish Museum of Natural History and the Universidad Nacional de Cordoba.

Figure 151. Distribution map of Solanum salamancae.