Solanum zuloagae Cabrera, Hickenia 1(41): 225. 1980.

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

62. Solanum zuloagae Cabrera, Hickenia 1(41): 225. 1980.

Figs 187 , 188

Type.

Argentina. Jujuy: Dpto. Palpalá, Mina 9 de Octubre, Sierra de Zapla , subida a la antenna, 24 Jan 1975, F.O. Zuloaga & N.B. Deginani 225 (holotype: SI [003663, acc. # 074662]) .

Description.

Erect or spreading perennial herbs or subwoody shrubs, to 2 m high or spreading to 2 m diameter. Stems terete, sparsely pubescent with spreading eglandular 2-8-celled simple uniseriate trichomes to 1.5 mm long, these drying white; new growth densely to moderately pubescent with simple uniseriate eglandular trichomes like those of the stems, on the leaves these mostly along the veins; bark of older stems green to pale brown. Sympodial units difoliate, the leaves more or less geminate, those of a pair equal in size and shape. Leaves simple, entire or rarely shallowly toothed, the blades 3.5-16 cm long, 2.5-7.5 cm wide, elliptic to narrowly elliptic, widest at the middle, membranous, concolorous; adaxial surfaces very sparsely and evenly pubescent with 4-6-celled eglandular simple uniseriate trichomes to 1.5 mm long, appearing glabrous to the naked eye; abaxial surfaces similarly sparsely pubescent, but with slightly denser pubescence along the veins; principal veins 5-7 pairs, drying yellowish green or brown, more pubescent than the lamina; base attenuate and somewhat decurrent onto the petiole; margins entire or shallowly toothed, if toothed the teeth to 2 mm long, all margins ciliate-pubescent with antrorse 2-6-celled eglandular simple uniseriate trichomes to 1 mm long, these drying white; petiole 0.5-1 cm long, sparsely pubescent like the stems and leaves. Inflorescences internodal, forked to several times branched, 4-8 cm long, with 20-40 flowers, moderately to densely pubescent with weak, spreading eglandular simple uniseriate trichomes to 1 mm long; peduncle 1.5-4 cm long; pedicels 0.8-1.1 cm long, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter at the apex, tapering, spreading at anthesis, sparsely to moderately pubescent like the stems and inflorescence axis, articulated at the base, leaving small stumps along the axis; pedicel scars irregularly spaced 1.5-5 mm apart, slightly raised from the axis. Buds globose to broadly ellipsoid, the corolla strongly exserted from the calyx before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube ca. 0.5 mm long, conical, the lobes 1.1-5 mm long, 0.5-1 mm wide, sometimes unequal in length in the same flower, narrowly triangular, sparsely to moderately pubescent like the rest of the inflorescence, the trichomes eglandular, simple, uniseriate and drying white. Corolla 1.2-1.8 cm in diameter, white, stellate, lobed ca. 3/4 of the way to the base, the lobes 3-7 mm long, 3-5 mm wide, deltate, spreading to reflexed at anthesis, adaxially glabrous, abaxially densely papillate with 1-3-celled trichomes over entire surface. Stamens equal; filament tube ca. 0.5 mm long; free portion of the filaments ca. 0.5 mm long, pubescent with transparent, tangled eglandular simple uniseriate trichomes adaxially; anthers 3-3.5 mm long, 1.25-1.5 mm wide, broadly ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 5-6 mm long, straight, exserted beyond the anther cone, densely pubescent in the lower half where included in the anther cone; stigma small-capitate, the surface minutely papillose. Fruit a globose berry, 0.4-0.5 cm in diameter, green (?) when mature, the pericarp thin, matte, opaque, glabrous; fruiting pedicels 0.8-1.1 cm long, ca. 0.5 mm in diameter at the base, ca. 0.5 mm in diameter at the apex, not markedly woody, spreading, not persistent; fruiting calyx not accrescent, the lobes appressed to the berry to slightly reflexed. Seeds ca. 30 per berry, ca. 1.2 mm long, ca. 1.2 mm wide, not markedly flattened, round or somewhat teardrop shaped, pale yellowish tan, the surfaces minutely pitted, the testal cells sinuate in outline near the centre of the seed, more rectangular at the margins. Stone cells 8 per berry, 4 larger ca. 1 mm in diameter, 4 smaller ca. 0.5 mm in diameter, cream-coloured, the surfaces occasionally ornamented (Barboza 2202). Chromosome number: n = 12 ( Moyetta et al. 2013, voucher Barboza et al. 3569).

Distribution

(Fig. 189 ). Solanum zuloagae occurs in the Andes of northern Argentina (Provs. Jujuy, Salta, Tucumán) and Bolivia (Depts. Cochabamba, Chuquisaca, Santa Cruz).

Ecology and habitat.

Solanum zuloagae grows in understorey of moist forests or ‘yungas’, often at clearing edges or scrambling over other vegetation in treefalls or roadside, from 640 to 2,940 m elevation.

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 144,608 km2 [LC]; AOO = 108 km2 [EN]. Solanum zuloagae is a plant of roadsides and disturbed areas and occurs over a relatively wide range. The small AOO may be a result of collecting deficit but bears consideration. It has been found within protected areas in Argentina (e.g., Yungas Biosphere Reserve, Parque Nacional Baritú) and in the region of Parque Nacional Carrasco in Bolivia.

Discussion.

Solanum zuloagae is most similar morphologically to S. huayavillense , with which it is broadly, but not locally, sympatric. The species share large, membranous leaves with ciliate margins, lax stems that zig-zag over other vegetation, small flowers with stubby anthers and small fruits. Solanum zuloagae can be distinguished from S. huayavillense by calyx morphology (tube shorter than lobes versus longer than lobes in S. huayavillense ), corolla colour (white versus yellow) and slightly longer (3-3.5 mm long versus 2.5-3 mm long) anthers. Berries of S. zuloagae consistently have eight stone cells of two sizes, while those of S. huayavillense either have four or the stone cells are completely absent.

Figures

Figure 187. Solanum zuloagae A flowering and fruiting branch B flower C calyx D eglandular trichome of the calyx E sector of the dissected flower F eglandular trichome of the corolla G stamen, dorsal view H stamen, ventral view I eglandular trichome of the filament J gynoecium K infructescence L fruit M seed N embryo (A-N Barboza et al. 2208). Illustration by P. Peralta. Previously published in Barboza et al. (2013: 263)

Figure 188. Solanum zuloagae A habit B ciliate leaf margins C inflorescence with buds and flowers at full anthesis D maturing fruits (A-D Barboza et al. 3569). Photos by S. Knapp.

Figure 189. Distribution map of Solanum zuloagae.