Solanum antisuyo Saerkinen & S.Knapp, PhytoKeys 44: 47. 2015.

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

6. Solanum antisuyo Saerkinen & S.Knapp, PhytoKeys 44: 47. 2015.

Figs 4D, E , 21 , 22

Type.

Peru. Cusco: Prov. Paucartambo, 1 km from Puesto de Vigilancia of Parque Nacional de Manu on road from Paucartambo to Pilcopata coming from Puesto , 13°12'05"S, 71°37'21"W, 3,480 m, 15 Mar 2012, S. Knapp, P. Gonzáles, A. Matthews & T. Särkinen 10435 (holotype: USM (acc. # 00268057); isotypes: BM [BM001114929], F, HUSA, HUT, MO) .

Description.

Stout herbs or subwoody shrubs up to 1.5 m high, much branching at base, the individual branches up to 1 m long. Stems 2-ridged or slightly winged especially towards base, 0.4-0.6 cm in diameter, purple-coloured especially at leaf nodes, nearly glabrous, sparsely pubescent with simple uniseriate, much reduced 1-3-celled trichomes especially on the often purple-coloured young growth. Sympodial units difoliate, not geminate. Leaves simple, the blades 2-17 cm long, 1.2-8.4 cm wide, broadly ovate-lanceolate, widest in the lower third, membranous to somewhat fleshy, slightly discolorous; adaxial and abaxial surfaces sparsely pubescent with more or less appressed 1-3-celled simple uniseriate trichomes 0.1-0.2 mm long; principal veins 7-10 pairs; base rounded, decurrent on the petiole; margins entire, often purple tinged; apex acute to acuminate; petiole 0.3-1.2 cm long, occasionally narrowly winged, sparsely pubescent with simple uniseriate trichomes like those of the stems and leaves. Inflorescences internodal, unbranched or forked, 1.4-4 cm long, with 5-14 flowers arising very close together, sparsely pubescent with appressed 1-2-celled simple uniseriate trichomes similar to those on stem and leaves; peduncle 1-3.3 cm long, if the inflorescence branched then the peduncle 0.2-0.4 cm long, short and congested; pedicels 1-1.2 cm long, 0.5-0.6 mm in diameter at the base expanding gradually to 1-1.2 mm in diameter at apex, straight and spreading at anthesis, recurving and becoming woody in fruit, not dehiscing; pedicel scars spaced 0-2 mm apart. Buds conical-ellipsoid, cream-coloured, the corolla strongly exserted from the calyx tube before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1.5-2 mm long, green, the lobes 0.7-0.9 mm long, broadly deltate with rounded apices, purple-coloured, sparsely pubescent with 1-celled simple uniseriate trichomes. Corolla 1.2-2.4 cm in diameter, stellate, white or rarely lilac with a yellow to yellow-green central star at the base, lobed slightly less than halfway to the base, the lobes ca. 9-15 mm long, 4-5 mm wide, spreading to reflexed at anthesis, pubescent abaxially with 1-3-celled simple uniseriate trichomes shorter than the trichomes of the stems and leaves, sparsely pubescent adaxially at base near the filaments with 5-7-celled simple uniseriate trichomes. Stamens equal or slightly unequal; filament tube ca. 2 mm long, adaxially pubescent with 5-7-celled simple uniseriate trichomes; free portion of the filaments ca. 2 mm long, sometimes slightly longer in two lowermost anthers at anthesis (perhaps elongating late in anthesis), pubescent like the tube; anthers ca. (2.8)3-3.4 mm long, 1 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary cylindrical, pubescent 2/3 from the base with 2-3-celled simple uniseriate trichomes; style ca. 6 mm long, straight, exserted beyond the anther cone, densely pubescent up to 2/3 of the length with 2-3-celled simple uniseriate trichomes at the base; stigma globose, minutely papillate, pale yellow in live plants. Fruit an ellipsoid berry, 0.8-1.1 cm in diameter, green turning translucent yellowish green to deep purple when ripe, the pericarp relatively thick, shiny, somewhat translucent, glabrous; fruiting pedicels 1.1-2.2 cm long, ca. 1 mm in diameter at the base and 1.5 mm at apex, deflexed and woody in fruit, purple-coloured, persistent and remaining on the plant after fruit drops; fruiting calyx lobes tightly appressed to the berry, purple-coloured, calyx often splitting into two larger lobes. Seeds 35-45 per berry, ca. 1.1 mm long, ca. 1.7 mm wide, concave-reniform, narrower at one end, brown, the hilum positioned sub-laterally towards the narrower end, the testal cells pentagonal in outline. Stone cells (0)2 per berry, usually equatorially positioned, ca. 1 mm in diameter, cream-coloured. Chromosome number: not known.

Distribution

(Fig. 23 ). Solanum antisuyo occurs primarily on the eastern Andean slopes in Ecuador (Prov. Azuay, Bolívar, Chimborazo, Cotopaxi, Loja, Napo, Pichincha, Zamora-Chinchipe), Peru (Depts. Amazonas, Cusco, Huánuco, Pasco, Piura, Puno), and Bolivia (Depts. Cochabamba, La Paz).

Ecology and habitat.

Solanum antisuyo is primarily found growing in secondary vegetation, disturbed roadsides, landslides, and gravelly slopes in 'ceja de selva’ (forest edges at treeline), montane cloud forest and Polylepis ( Rosaceae ) forests; from (1,000-) 2,000 to 3,600 (-3,900) m in elevation.

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 1,089,690 km2 [LC]; AOO = 400 km2 [LC]. Solanum antisuyo grows readily in disturbed sites and combined with its wide range, it appears to have relatively low threat status despite the generally increasing human pressure and habitat destruction in the Andes. It occurs within protected areas in both Peru (Parque Nacional Manu) and Bolivia (Parque Nacional Madidi).

Discussion.

Solanum antisuyo is morphologically most similar to S. polytrichostylum with which it has been conflated in the past. It can be distinguished by its usually simple inflorescences where pedicels are spaced ca. 1-3 mm apart along the short flowering-bearing portion of the axis compared to consistently branched inflorescences with the flowers congested at the branch tips in S. polytrichostylum ; bud morphology also differs with the buds of S. polytrichostylum always somewhat elongate and usually cream with purple stripes, while those of S. antisuyo are more ellipsoid and usually of a single colour. The fruits of S. antisuyo are somewhat ellipsoid and borne on pedicels that markedly enlarge towards the apex as compared to the spherical berries on less obviously expanded pedicels of S. polytrichostylum . The the seeds also differ in colour (brown in S. antisuyo versus yellow in S. polytrichostylum ). Solanum antisuyo has the calyx tube longer than the smaller, purple-tinged calyx lobes while S. polytrichostylum has calyx tubes shorter than the slightly larger, triangular calyx lobes; the styles of S. polytrichostylum are always more exserted (2-4 mm versus 1-2 mm beyond the anther cone) than those of S. antisuyo ; fruiting pedicels of S. antisuyo persist after fruit drop (see Fig. 22D ), while those of S. polytrichostylum generally do not. The two species are also ecologically somewhat distinct, with S. polytrichostylum restricted to streams and moist roadsides, and S. antisuyo is found in drier areas in gravel, disturbed areas, and landslides. Other sympatric members of the Morelloid clade without glandular trichomes with which S. antisuyo could be confused include S. cochabambense that has smaller, spherical fruits, larger violet corollas that are more rotate in outline, and denser indumentum with longer 3-7-celled simple hairs, and S. pallidum that has branched rather than simple hairs.

Variation in growth form and flower colour can be observed in the field, where individuals growing in more humid conditions grow into stout herbs to ca. 1.5 m high, while individuals in drier, higher elevation habitats in rocky landslides are stunted herbs reaching only ca. 40 cm in height. Colour variation in corolla is common within morelloids and Solanum species in general; most specimens of S. antisuyo have creamy white petals, but occasional specimens with lilac corollas are known (e.g., Särkinen et al. 4048, 4049, and 4053).

Figures

Figure 4. Representative fruits, seeds and stone cells of South American morelloids A bilobed fruits in S. tripartitum with fully mature red berries at the base of the inflorescence and maturing green, yellow, and orange fruits more distally B orange-red fleshy berries of S. corymbosum in highly branched inflorescences C fully mature marbled fruits in S. physalifolium D immature ellipsoid fruits of S. antisuyo E fully mature fruits of S. antisuyo F immature green fruits amongst fully mature purple-black fruits in S. cochabambense G fully mature fruits of S. polytrichostylum H stone cells (also known as sclerotic granules or brachysclerids) found in the fruits of most species of the Morelloid clade (left side of photo) next to the teardrop shaped seeds (right side of photo; S. umalilaense Manoko) I stone cells visible in dried fruits of herbarium specimens (S. triflorum). (A Barboza 3563 B Saerkinen et al. 4604 B C Knapp et al. 10334 D Gonzales 10256 E Gonzales 10256 F Knapp et al. 10363 G Saerkinen et al. 5277 H Nijmegen accession A 24750133 I Podlech 8624 BM 000848286). Photos by P. Gonzales, S. Knapp, and T. Saerkinen.

Figure 21. Solanum antisuyo A flowering branch B fruiting branch C stem with a leaf node D detail of abaxial leaf surface E detail of adaxial leaf surface F flower bud G dissected flower H fruit (A-H Knapp et al. 10435). Illustration by R. Wise.

Figure 22. Solanum antisuyo A habit in rocky landslide B buds and flowers, showing the distinct calyx with long tube and minute, but somewhat fleshy, purplish green lobes C slightly ellipsoid fruits with deflexed pedicels, with appressed calyx lobes often splitting in fruit D woody pedicels of the infructescence (A, B Knapp et al. 10399 C Knapp et al. 10401 D Knapp et al. 10435). Photos S. Knapp. Previously published in Saerkinen et al. (2015 c: 48).

Figure 23. Distribution map of Solanum antisuyo.