Solanum polytrichostylum Bitter, Repert. Spec. Nov. Regni Veg. 10: 550. 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

42. Solanum polytrichostylum Bitter, Repert. Spec. Nov. Regni Veg. 10: 550. 1912.

Figs 4G , 128 , 129

Solanum violaceistriatum Bitter, Repert. Spec. Nov. Regni Veg. 10: 550. 1912. Type. Bolivia. La Paz, Caminos, 14 May 1906, O. Buchtien 119 (no herbaria cited; lectotype, designated here: US [00610902, acc. # 700077]; isolectotypes: NY [00172242], S [acc. # S04-2996], US [00027850, acc. # 1175820]).

Solanum irenaeum Bitter, Repert. Spec. Nov. Regni Veg. 10: 551. 1912. Type. Bolivia. La Paz: vic. La Paz, 1889, M. Bang 31 [a] (holotype: B [destroyed, as "Bang 31 p.p."]; lectotype, designated here: NY [00173050]; isotypes: BM [BM000617674], BR [BR0000005538546], CAL [acc. # 316753], E [E00279514], G [G00343341], MO [MO-503695, acc. # 1815479], NY [00172051], PH [00030429], US [00027629, acc. # 1324595], W [acc. # 1895-0000969, acc. # 1890-0001435], WIS [v0256195WIS]).

Solanum medianiviolaceum Bitter, Repert. Spec. Nov. Regni Veg. 10: 562. 1912. Type. Bolivia. La Paz: La Paz, O. Buchtien 2968 (holotype: "herb. Buchtien"; lectotype, designated here: US [00027675, acc. # 1133299]; isolectotypes: GOET [GOET003549, GOET003550, GOET003551. GOET003552], NY [00172085, 00172086], US [00610903, acc. # 700120]).

Solanum aloysiifolium Dunal var. polytrichostylum (Bitter) Edmonds, Bot. J. Linn. Soc. 75: 171. 1977. Type. Based on Solanum polytrichostylum Bitter.

Type.

Bolivia. La Paz: Nor Yungas, Unduavi , 3,200 m, 12 Dec 1907, O. Buchtien 763 (holotype: "herb. Buchtien "; lectotype, designated here: US [00027753, acc. # 700087]; isolectotypes: M [M-0171818], NY [00172137]).

Description.

Erect herbs to single-stemmed shrubs 1-2.5 m high, the branches erect and ascending. Stems terete, sparsely pubescent with a few scattered white eglandular simple uniseriate 2-6-celled trichomes to 0.5 mm long, soon glabrescent; new growth densely appressed-pubescent with white eglandular simple uniseriate trichomes to 1 mm long; bark of older stems greenish brown, glabrescent. Sympodial units difoliate, the leaves not geminate. Leaves simple, the blades 3.3-18 cm long, 1.4-8 cm wide, elliptic to narrowly elliptic, widest at the middle, membranous, concolorous; adaxial surfaces almost glabrous with a few tiny eglandular simple uniseriate trichomes ca. 0.2 mm long, these more commonly found along the veins; abaxially glabrous on the lamina, moderately pubescent with eglandular simple uniseriate trichomes ca. 0.2 mm long on the veins; principal veins 8-9 pairs, moderately white-pubescent abaxially; base attenuate; margins entire or occasionally with a few small teeth to 2 mm long in the basal part of the blade; apex acuminate; petioles 0.6-2.5 cm long, not markedly winged, very sparsely pubescent with simple uniseriate trichomes like those of the leaf venation. Inflorescences internodal or opposite the leaves at branching points, many times branched, 5-10 cm long, with 10-50 flowers clustered at the tips of the branches, sparsely pubescent with white eglandular simple uniseriate 2-6-celled trichomes like those of the stems, but these weak and tangled; peduncle 2-5 cm long; pedicels 1-13 cm long, ca. 1 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, slightly tapering, spreading at anthesis, sparsely pubescent with tangled trichomes like those of the rest of the inflorescence, articulated at the base; pedicel scars tightly spaced at the tips of inflorescence branches. Buds narrowly ellipsoid, ellipsoid to slightly ovate and flattened at the tip, wider in the lower third, the corolla strongly exserted from the calyx before anthesis, in live plants the buds markedly striped with purple and white. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1-1.5 mm long, cup-shaped, the lobes 1-1.5 mm long, ca. 1 mm wide, deltate with a distinct mucro ca. 0.5 mm long from the obtuse tip, sparsely pubescent with white eglandular simple uniseriate 2-6-celled trichomes like the rest of the inflorescence. Corolla 1.9-2.2 cm in diameter, white with a dark purple petal midvein and a green eye, stellate to deeply stellate, lobed halfway to 3/4 of the way to the base, the lobes ca. 6 mm long, ca. 3 mm wide, narrowly deltate, spreading or reflexed, adaxially glabrous, abaxially sparsely papillate-puberulent, densely so on the tips and margins. Stamens equal; filament tube minute; free portion of the filaments 0.75-1 mm long, densely pubescent with tangled transparent simple uniseriate trichomes adaxially; anthers 4-4.5 mm long, ca. 1.2 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 6.5-9 mm long, straight, exserted beyond the anther cone, densely pubescent with tangled simple uniseriate trichomes to 0.4 mm long in the lower 2/3; stigma capitate to slightly bilobed, bright green in live plants, the surface minutely papillose. Fruit a globose or occasionally slightly flattened berry, 1-1.2 cm in diameter, green when immature, dark green when ripe, the pericarp thin, matte to slightly shiny, opaque but becoming slightly translucent on ripening, glabrous; fruiting pedicels 1.3-1.7 cm long, ca. 1 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, slightly woody, deflexed, not persistent; fruiting calyx not enlarged in fruit, the lobes appressed to the berry. Seeds 40-80 per berry, 1.5-2 mm long, 1-1.5 mm wide, flattened and teardrop shaped, pale tan, the surfaces minutely pitted, the testal cells sinuate in outline. Stone cells 6 per berry, 2 apical and 4 equatorial, ca. 0.7 mm in diameter, cream-coloured. Chromosome number: 2n = 24 ( Chiarini et al. 2017, voucher Knapp et al. 10384).

Distribution

(Fig. 130 ). Solanum polytrichostylum is a plant of Andean slopes from central Peru (Depts. Ancash, Apurímac, Ayacucho, Cajamarca, Cusco, Huancavelica, Junín, Lima, Pasco, Piura) and Bolivia (Depts. Cochabamba, La Paz). In Peru it has been collected both on the eastern and western slopes of the Andes.

Ecology and habitat.

Solanum polytrichostylum grows in wet forests and cloud forests ( ‘yungas’), often in marginal sites or landslides, from 2,000 to 4,000 m elevation.

Common names and uses.

Peru. Cusco: ccaya-ccaya (Herrera 3022). No uses recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 432,164 km2 [LC]; AOO = 244 km2 [EN]. Solanum polytrichostylum is widely distributed and is a plant of disturbed areas wherever it occurs. It is found within the World Heritage Site of Machu Picchu (Peru) and is common among protected archaeological sites in the Sacred Valley of Cusco (e.g., Ollantaytambo [Ullantaytampu], Pisac).

Discussion.

Solanum polytrichostylum is a coarse erect herb morphologically very similar to S. antisuyo , with which it is broadly sympatric. It differs from S. antisuyo in its more elliptic (rather than ovoid) buds that are prominently striped with purple and white in both live and dried plants (Fig. 131C, D ), flowering pedicels without a strong taper (as opposed to strongly tapered), its longer calyx lobes (1-1.5 mm versus 0.6-0.9 mm) with a distinct mucro apically and the larger number of stone cells in mature berries (6 versus 0-2). The anthers of S. polytrichostylum are slightly longer (4-4.5 mm long) than those of S. antisuyo (3-3.4 mm long), but this can be difficult to measure. The most reliable characters for identification are the bud shape and pedicel tapering, although S. polytrichostylum generally has more branched inflorescences than does S. antisuyo . Solanum polytrichostylum often grows in dense stands along river edges in otherwise cultivated areas.

Bitter (1912a) cited a specimen from "herb. Buchtien" as the sole element for S. polytrichostylum . Buchtien’s Herbarium was acquired by the US National Herbarium during Paul C. Standley’s curatorship ( Morton and Stern 1966), so we have lectotypified S. polytrichostylum with the sheet in US (barcode 00027753, acc. # 700087).

In the same publication Bitter (1912a) described all of the rest of the names we here recognise as synonyms of S. polytrichostylum . Solanum violaceistriatum was described citing Buchtien 119, but with no herbarium indicated; we lectotypify this with the sheet in US (barcode 00610902, acc. # 700077) with the date of collection cited in the protologue, and an annotation of this species name in Buchtien’s hand. The protologue of S. irenaeum cited Bang 31 pro parte from Berlin ("herb. Berol."). This specimen is no longer extant and duplicates of Bang 31 are a mixed collection of S. polytrichostylum and S. pallidum (see under S. pallidum ). We select here as the lectotype for this name the duplicate of Bang 31 in NY (barcode 00173050) with both flowers and fruits that has the original determination ("S. nudum HBK") crossed out and " S. irenaeum Bitter sp. n." written in Rusby’s hand. Solanum medianiviolaceum was based on Buchtien 2968 ("herb. Boliv."); we lectotypify this name with the sheet in US from Buchtien’s herbarium (US barcode 00027675, acc. # 1133299) annotated as " Solanum medianiviolaceum Bitt. n.sp." in Buchtien’s hand.

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 128. Solanum polytrichostylum A flowering and fruiting habit B detail of adaxial leaf surface C Detail of abaxial leaf surface D inflorescence in bud E flower bud F dissected flower G fruit (A Buchtien 8754 B, C, E-G Monro et al. 3982 D Knapp et al. 10274). Illustration by R. Wise.

Figure 129. Solanum polytrichostylum A habit B inflorescence with buds C flowers at full anthesis D infructescence with maturing fruits (A Saerkinen & Correa 5277 B Knapp et al. 10439 C Knapp et al. 10414 D Knapp et al. 10437). Photos by S. Knapp.

Figure 130. Distribution map of Solanum polytrichostylum.

Figure 131. Solanum profusum A habit B flowering branch C flower bud D flower E calyx F glandular trichome of the calyx G dissected flower H stamen, dorsal view I stamen, ventral view J glandular trichome of the filament K gynoecium L eglandular trichome of the style (A-L Balls 5915). Illustration by P. Peralta. Previously published in Barboza et al. (2013: 255).