Solanum physalidicalyx Bitter, Repert. Spec. Nov. Regni Veg. 11: 212. 1912.

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

39. Solanum physalidicalyx Bitter, Repert. Spec. Nov. Regni Veg. 11: 212. 1912.

Figs 119 , 120

Solanum physalidicalyx Bitter var. integrascens Bitter, Repert. Spec. Nov. Regni Veg. 11: 213. 1912. Type. Argentina. Salta: Pasaje del Rio Juramento, P.G. Lorentz & G. Hieronymus s.n. (no explicit type material located; likely homotypic with the species).

Solanum physalidicalyx Bitter var. plurilobulatum Bitter, Repert. Spec. Nov. Regni Veg. 11: 213. 1912. Type. Argentina. Salta: Pasaje del Rio Juramento, P.G. Lorentz & G. Hieronymus s.n. (no explicit type material located; likely homotypic with the species).

Type.

Argentina. Salta: Pasaje del Rio Juramento , Feb 1873, P.G. Lorentz & G. Hieronymus 364 (lectotype, designated by Barboza et al. 2013, pg. 262: GOET [GOET003574]; isolectotypes: CORD [CORD00004269], DR [ DR054234 ], US [00027741, acc. # 282274).

Description.

Annual (?) or perennial herbs, the branches 0.3-1.3 m long, spreading and sprawling when large, viscid to the touch, somewhat woody at the base. Stems terete, viscid, densely pubescent with transparent glandular simple 3-5-celled uniseriate trichomes of varying lengths to 2.5 mm long and shorter simple uniseriate glandular trichomes, the glands unicellular; new growth densely pubescent with glandular papillae and transparent glandular simple uniseriate trichomes to 5-celled and 2 mm long; bark of older stems pale yellow when dry, remaining viscid to the touch. Sympodial units difoliate, the leaves not geminate. Leaves simple or shallowly crenate, the blades (1.2)2.5-8(9) cm long, (0.7)1-4.5(7.5) cm wide, ovate to broadly elliptic, widest at the middle or in the lower half, membranous, concolorous, viscid to the touch, extremely variable in size within a plant; adaxial surfaces sparsely to moderately but evenly glandular-pubescent with transparent simple uniseriate trichomes ca. 1 mm long, these denser along the veins; abaxial surfaces sparsely and evenly pubescent with similar glandular simple uniseriate trichomes, or the trichomes only on the veins; principal veins 4-6 pairs, glandular-pubescent; base abruptly truncate; margins entire or irregularly crenate, the lobes 1-2 mm long; apex acute; petiole (0.5)1-3(5) cm long, densely glandular pubescent like the stems, the pubescence denser on adaxial surface. Inflorescences opposite the leaves or occasionally internodal (ca. 1 mm away from leaf), unbranched, 1-2.5(4) cm long, with 3-8(10) flowers in the distal half, densely glandular-pubescent with transparent simple uniseriate trichomes 1-1.5 mm long and shorter glandular papillae; peduncle 0.5-2 cm long; pedicels 0.8-1 cm long, ca. 0.4 mm in diameter at the base, ca. 0.5 mm in diameter at the apex, gradually tapering, spreading at anthesis, densely glandular-pubescent with transparent, simple uniseriate trichomes to 1 mm long, articulated at the base but leaving a small raised stump ca. 0.3 mm long; pedicel scars evenly spaced ca. 1.5 mm apart, more crowded distally. Buds ellipsoid, the corolla just exserted from the calyx lobe tips before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1.5-2 mm long, conical, the lobes 1.5-3 mm long, deltate to triangular, densely glandular-pubescent with transparent simple uniseriate trichomes to 1.5 mm long. Corolla 1.2-1.4 cm in diameter, white with a pale yellowish green central star, this sometimes edged with purple, stellate, lobed ca. halfway to the base, the lobes 4-5 mm long, 3-5 mm wide, deltate, spreading or slightly reflexed at anthesis, glabrous adaxially, sparsely glandular-pubescent over the entire surface abaxially, the trichomes denser at the tips. Stamens equal; filament tube minute; free portion of the filaments 0.25-0.5 mm long, pubescent with transparent, tangled eglandular simple uniseriate trichomes adaxially; anthers (2.6)3-3.5(4) mm long, 1-1.2 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous or with a few glandular papillae apically; style 6-7 mm long, curved upwards distally, exserted beyond the anther cone, densely papillate in the lower third inside the anther cone; stigma globose, the surface minutely papillate, green in live plants. Fruit a globose berry, 0.6-0.8 cm in diameter, green or marbled green (Hunziker 10997) at maturity, completely enclosed in the accrescent, inflated calyx, the pericarp thin, shiny, translucent, glabrous; fruiting pedicels ca. 1.5 cm long, ca. 0.5 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, strongly deflexed with a distinct bend at the base, not markedly woody, not persistent; fruiting calyx accrescent and inflated, loosely and completely covering the berry, the base invaginate, the tube to 1.5 cm long, the lobes ca. 5 mm long, ca. 3 mm wide, pointed at the tips, the tube expanding more than the lobes, remaining viscid pubescent. Seeds 10-25 per berry, 2-2.5 mm long, 1.5-2 mm wide, flattened and teardrop shaped, reddish brown, the surfaces minutely pitted, the testal cells sinuate in outline with elongate “hairy” lateral walls to 0.25 mm long at maturity. Stone cells absent or 2 apical, ca. 0.5 mm in diameter, creamy white. Chromosome number: not known.

Distribution

(Fig. 121 ). Solanum physalidicalyx occurs from southern Bolivia (Depts. Santa Cruz, Tarija) to central Argentina (Provs. Catamarca, Córdoba, Jujuy, La Rioja, Tucumán, Salta, San Luis, Santiago del Estero).

Ecology and habitat.

Solanum physalidicalyx grows in dry forests and Chaco woodlands, often in the shade of trees or hedges, from 300 to 2,500 m elevation (two collections from Salta have elevations of 2,700 to 3,100 m).

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 605,225 km2 [LC]; AOO = 312 km2 [EN]. Solanum physalidicalyx is not as common as the very similar S. tweedieanum , but it has a similarly wide distribution and is a plant of disturbed areas. It appears not to have been collected within protected areas in Argentina.

Discussion.

Solanum physalidicalyx had long been recognised as a synonym of S. tweedieanum ( Edmonds 1972; Barboza et al. 2013) a morphologically similar glandular-pubescent species, but Knapp et al. (2020) recognised it as distinct and unravelled the complex set of names surrounding these two species. Solanum physalidicalyx differs from S. tweedieanum in its conspicuously inflated calyx in fruit (as opposed to merely accrescent and tightly investing the berry) and in its anthers 3-3.5 mm long (versus 4-5 mm in S. tweedieanum , although some overlap can occur). The two species are partly sympatric in Argentina and in the absence of mature fruit, can be very difficult to distinguish, although in general plants of S. physalidicalyx are more herbaceous and delicate (usually annuals?) than those of S. tweedieanum , which are woody and rhizomatous.

In Flora Argentina Barboza et al. (2013) recognised two species, S. tweedieanum (as " S. tweedieanum ", a misspelling) and S. atriplicifolium , both glandular-pubescent with ovate, shallowly toothed leaves. Solanum physalidicalyx was erroneously put into synonymy with S. tweedieanum ; the type of S. tweedieanum is a better match for those plants they called S. atriplicifolium , which is here treated as a synonym of S. tweedianum The type of S. tweedieanum comes from a plant cultivated at Kew that was collected in flower only; it lacks the diagnostic calyx characters that enable easy identification in this group, but anther length can also be used to distinguish those plants not in fruit. See Knapp et al. (2020) for a complete discussion and comparison of these glandular-pubescent plants.

The chromosome count of 2n = 24 reported by Edmonds (1972) is based on a voucher (Hawkes et al. 3204) we have been unable to locate. From the locality (between Mina Clavero and Villa Dolores in Córdoba, Argentina) this could represent either S. tweedieanum or S. physalidicalyx .

Details of typification of S. physalidicalyx and the issues with its synonyms are treated in Knapp et al. (2020).

Figures

Figure 119. Solanum physalidicalyx A flowering and fruiting branch B flower C stamen, ventral view D gynoecium E fruit (A-E Cabrera 14409). Illustration by M. T. Cabrera. Previously published in Barboza et al. (2013: 262), as " S. tweedianum ".

Figure 120. Solanum physalidicalyx A habit B flowering branch C developing infructescence D maturing fruits (A-D Barboza 4210). Photos by G. E. Barboza. Previously published in part in Knapp et al. (2020: 39).

Figure 121. Distribution map of Solanum physalidicalyx.