Solanum juninense Bitter, Bot. Jahrb. Syst. 54, Beibl. 119: 11. 1916.

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

27. Solanum juninense Bitter, Bot. Jahrb. Syst. 54, Beibl. 119: 11. 1916.

Figs 2C , 83 , 84

Type.

Peru. Junín: Cerca de Huancayo , 11 Apr 1913, A. Weberbauer 6598 (no herbaria cited; lectotype, designated here: MOL [MOL00005056]; isolectotypes: B, destroyed [F neg. 2613], F [v0043244F, acc. # 627963; v0043245F, acc. # 847835, fragment of specimen from B], MOL [MOL00005057, MOL00005058], US [00027639, acc. # 1473478; 01014171, acc. # 1444708]).

Description.

Scrambling shrubs or woody herbs to 1 m high, the branches lax and supported by other vegetation. Stems terete, densely pubescent with transparent glandular 6-8-celled simple uniseriate trichomes to 2 mm long, the gland single-celled, globose; new growth densely pubescent with sessile glands and transparent glandular 6-8-celled simple uniseriate trichomes to 2 mm long; bark of older stems pale yellowish green or brown, glabrescent. Sympodial units plurifoliate, the leaves not geminate. Leaves simple, occasionally shallowly toothed, the blades 2.5-8 cm long, 0.8-5.3 cm wide, elliptic, elliptic-ovate or narrowly ovate, widest in the lower half, membranous, slightly discolorous; adaxial surfaces sparsely to moderately pubescent with transparent glandular simple uniseriate trichomes 1-2 mm long; abaxial surfaces glabrous to sparsely glandular-pubescent on the lamina, densely pubescent with transparent glandular simple uniseriate trichomes 1-2 mm long along the veins; principal veins 5-6 pairs, densely glandular-pubescent abaxially; base acute to cuneate; margins entire to undulate or very shallowly and irregularly toothed, if present the teeth 1-2 mm long, 1-2 mm wide, rounded at the tips, the sinuses rounded and reaching to less than 1/10 of the way to the midrib; apex acute to acuminate; petioles 0.5-3.5 cm long, moderately to densely pubescent with transparent glandular 6-8-celled simple uniseriate trichomes to 2 mm long, the gland single-celled. Inflorescences terminal at branch tips or more rarely internodal, forked or very occasionally more branched, 3-5 mm long, with (4)10-20 flowers clustered in the distal half of the branches, densely pubescent with transparent glandular 6-8-celled simple uniseriate trichomes to 2 mm long, the gland single-celled; peduncle 1-3 cm long; pedicels 0.5-0.8 cm long, ca. 0.5 mm in diameter at the base, ca. 0.75 mm in diameter at the apex, slightly tapering, spreading at anthesis, pubescent with transparent glandular 6-8-celled simple uniseriate trichomes like those of the inflorescence axes, articulated at the base, leaving a small raised bump; pedicel scars irregularly spaced 1-2 mm apart, slightly raised. Buds ellipsoid, the corolla strongly exserted from the calyx before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1-1.5 mm long, conical, the lobes 1.5-2 mm long, ca. 1 mm wide, triangular with acute tips, pubescent with transparent glandular 6-8-celled simple uniseriate trichomes ca. 1 mm long, the gland single-celled. Corolla 1.2-1.5 cm in diameter, white, pale lilac to deep purple, with a darker purple or greenish purple eye, stellate, lobed 1/3 to 1/2 of the way to the base, the lobes 4-5 mm long, 3.5-7 mm wide, broadly deltate, spreading at anthesis, adaxially glabrous, abaxially densely pubescent with transparent mixed eglandular and glandular simple uniseriate trichomes to 0.5 mm long, densely papillate on tips and margins. Stamens equal; filament tube minute; free portion of the filaments 1.5-2 mm long, glabrous or sparsely pubescent with tangled transparent simple uniseriate trichomes abaxially; anthers 3-3.5 mm long, ca. 1 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 5-7 mm long, straight, exserted beyond the anther cone, densely glandular-pubescent in the lower half with transparent trichomes; stigma small-capitate, the surface minutely papillate. Fruit a globose berry, 0.7-0.9 cm in diameter, greenish purple or dark green when ripe, the pericarp thin, shiny, translucent, glabrous; fruiting pedicels 0.8-0.9 cm long, ca. 1 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, not markedly woody, spreading or deflexed, not persistent; fruiting calyx not markedly enlarged or accrescent, the lobes to 2.5 mm long, spreading or appressed to the berry. Seeds 40-50 per berry, ca. 2 mm long, ca. 1.5 mm wide, flattened and teardrop shaped, pale straw-coloured, the surfaces minutely pitted, the testal cells rectangular in outline with thick walls. Stone cells (1)2 per berry, scattered in mesocarp, 0.75-1 mm in diameter, cream-coloured. Chromosome number: 2n = 24 ( Chiarini et al. 2017, voucher Särkinen et al. 4754).

Distribution

(Fig. 85 ). Solanum juninense occurs in the Andes of Peru (Depts. Amazonas, Ancash, Ayacucho, Cajamarca, Huancavelica, Junín, La Libertad, Pasco, San Martin) and Bolivia (a single collection from Dept. La Paz, Solomon 16463). We expect to see more collections in the future from southern Peru and northern Bolivia, but currently there is a disjunction between the Peruvian and Bolivian populations.

Ecology and habitat.

Solanum juninense grows in cloud forests and cloud forest margins ('ceja de selva’), often in open roadsides, treefalls and along streams ditches and moist depressions, from 1,800 to 4,200 m elevation.

Common names and uses.

Peru. Junín: hierba mora (Marcelo Peña et al. 1895). No uses recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 197,081 km2 [LC]; AOO = 120 km2 [EN]. Solanum juninense has a relatively wide distribution and is found in at least two protected areas within its range (e.g., Parque Nacional Abiseo and Parque Nacional Yanachaga-Chemillén, Peru).

Discussion.

Solanum juninense is one of the few sticky-pubescent morelloids (with S. arenicola and S. subtusviolaceum ) without an accrescent calyx. It is most similar to S. subtusviolaceum , and both can be distinguished from other glandular-pubescent species by their non-accrescent fruiting calyces and highly branched inflorescences. Solanum arenicola is a plant of the Amazonian foothills, while both S. juninense and S. subtusviolaceum are Andean taxa. Solanum juninense differs from S. subtusviolaceum in its plurifoliate sympodia with elliptic to narrowly elliptic leaves (versus unifoliate or difoliate sympodia with ovate to rhomboid leaves), acute to cuneate leaf base (versus truncate in S. subtusviolaceum ), with shorter calyx lobes (1.5-2 mm long versus 2.5-3.5 mm long and sometimes toothed), slightly smaller corollas (1.2-1.5 cm in diameter versus 1.8-2 cm in diameter) with deltate rather than triangular lobes and one or two stone cells (versus four in S. subtusviolaceum ) in each berry.

Bitter (1916) described S. juninense citing a collection of August Weberbauer (Weberbauer 6598) but no herbarium. We select here the best preserved of the duplicates held in the herbarium of the Universidad Nacional Agraria La Molina (MOL00005056) as the lectotype. Weberbauer’s original personal herbarium is held in MOL.

Figures

Figure 2. Representative habits and leaves of South American morelloids A prostrate annual herbs (S. weddellii) B large lax shrubs (S. aloysiifolium) C roots forming along a creeping stem (S. juninense) D spinose processes on stems of many species (S. huayavillense) E glandular trichomes found in some members of the clade (S. glandulosipilosum) F dendritic / branched trichomes found in S. pallidum G regularly 3 - lobed leaves in S. palitans H highly variable leaves along a single stem in S. salicifolium (A Saerkinen et al. 4038 B Barboza et al. 3505 C Saerkinen et al. 4754 D Barboza et al. 3536 E Barboza et al. 3520 F Saerkinen et al. 4010 G Atchison & Gagnon 25 H Barboza et al. 3473). Photos by S. Knapp, G. Atchison, and T. Saerkinen.

Figure 83. Solanum juninense A habit B inflorescence with buds C developing fruit (A, C Weberbauer 6598 [MOL 00005056] B Weberbauer 6598 [vF 0043244 F]). Reproduced with permission of the Field Museum of Natural History and the Universidad Nacional Agraria La Molina.

Figure 84. Solanum juninense A habit B flowering branch C flowers at anthesis D maturing fruits (A-D Saerkinen et al. 4754). Photos by T. Saerkinen.

Figure 85. Distribution map of Solanum juninense.