Solanum pentlandii Dunal, Prodr. [A. P. de Candolle] 13(1): 51. 1852.

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

38. Solanum pentlandii Dunal, Prodr. [A. P. de Candolle] 13(1): 51. 1852.

Figs 3C , 116 , 117

Solanum coerulescens Bitter, Repert. Spec. Nov. Regni Veg. 10: 554. 1912. Type. Bolivia. La Paz: sin. loc., Apr 1910, O. Buchtien 2965 (no herbaria cited; lectotype, designated here: US [00027517, acc. # 703363]; isolectotypes: GOET [GOET003565, GOET003566], NY [00139098, 00139099], US [00610913, acc. # 1175828]).

Solanum coerulescens Bitter var. manophyes Bitter, Repert. Spec. Nov. Regni Veg. 10: 554. 1912. Type. Bolivia. La Paz: Caminos, 4 Jan 1907, O. Buchtien 769 (no herbaria cited; lectotype, designated here: US [00027518, acc. # 1175829]; isolectotypes: GH [00077600], GOET [GOET003568], NY [00139101], US [00610914, acc. # 1175823]).

Solanum coerulescens Bitter var. pycnophyes Bitter, Repert. Spec. Nov. Regni Veg. 10: 554. 1912. Type. Bolivia. La Paz: sin. loc., Apr 1910, O. Buchtien 2966 (no herbaria cited; lectotype, designated here: US [00027519, acc. # 1175974]; isolectotypes: GOET [GOET003567]; NY [00139100], US [00610915, acc. # 703364]).

Solanum insulae-solis Bitter, Repert. Spec. Nov. Regni Veg. 10: 563. 1912. Type. Bolivia. La Paz: Lake Titicaca, Isla del Sol ( “Sonneninsel”), Mar 1910, O. Buchtien 5856 (no herbaria cited; lectotype, designated here: US [00650475, acc. # 1175976]).

Type.

Bolivia. "E of La Paz ", J.B. Pentland s.n. (holotype: G-DC [G00144345]; isotype: P [P00367413]) .

Description.

Bushy small shrubs or herbs, 0.2-0.7 m high, to ca. 1 m spread, the branches more or less erect or spreading, slightly woody at the base. Stems strongly angled with wings to 1.5 mm wide and with abundant spinescent processes, glabrous to very sparsely pubescent with scattered white eglandular simple uniseriate 3-4-celled trichomes to 0.5 mm long, soon glabrescent; new growth moderately to densely pubescent with white eglandular simple uniseriate trichomes to 0.5 mm long; bark of older stems greenish brown, glabrescent. Sympodial units difoliate, the leaves usually not geminate. Leaves simple, usually more or less regularly toothed, the blades 2.1-10.5 cm long, 0.8-5.5 cm wide, ovate to broadly elliptic, occasionally narrowly elliptic, much larger on older stems, widest at the middle or just below, membranous to slightly rubbery, concolorous; adaxial and abaxial surfaces glabrous and shiny, with a few scattered white eglandular 3-4-celled simple uniseriate trichomes to 0.5 mm long like those of the stems; principal veins 7-9 pairs, usually slightly more pubescent that the lamina; base attenuate onto the petiole and the stem; margins usually strongly toothed, only occasionally entire or with few teeth near the base, the teeth 0.3-1.5 mm long, 0.4-1 mm wide, triangular with acute apices, the sinuses rounded, reaching ca. 1/8 to 1/5 of the way to the midrib; apex acute to acuminate; petioles winged from the decurrent leaf bases and then onto the stem, winged portion 0.5-3 cm long, glabrous. Inflorescences internodal, several times branched (occasionally only forked), 1-6 cm long, with 10-20 flowers at the tips of the branches or in the distal half, moderately to sparsely pubescent with white eglandular simple uniseriate trichomes to 0.5 mm long, usually more pubescent that the stems; peduncle 1-2 cm long; pedicels 0.9-1 cm long, ca. 0.5 mm in diameter at the base, ca. 0.75 mm in diameter at the apex, spreading at anthesis, sparsely pubescent with simple uniseriate trichomes like the rest of the inflorescence, articulated at the base, leaving a slight swelling on the axis; pedicel scars irregularly spaced 1-2 mm apart in the distal half of each inflorescence branch. Buds globose, the corolla ca. halfway exserted from the calyx before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1-1.5 mm long, conical or strongly cup-shaped, the lobes ca 1 mm long, 1-1.2 mm wide, broadly deltate, the tips obtuse to acute, strongly recurved in bud, sparsely pubescent with white eglandular simple uniseriate trichomes like the rest of the inflorescence. Corolla 0.9-1.2 cm in diameter, violet-blue, often edged white, with a green eye, stellate, lobed ca. 2/3 of the way to the base, the lobes 4-5 mm long, 3-4 mm wide, deltate, spreading to slightly reflexed at anthesis, adaxially glabrous, abaxially densely puberulent with white simple uniseriate trichomes ca. 0.2 mm long, these denser at the tips and margins. Stamens equal; filament tube minute; free portion of the filaments 0.6-1 mm long, sparsely pubescent with tangled transparent simple uniseriate trichomes adaxially; anthers 2-2.5 mm long, 1.2-1.5 mm wide, plump and ellipsoid, yellow, poricidal at the tips the pores lengthening to slits with age. Ovary conical, glabrous; style 5-6 mm long, straight (even in bud), markedly long-exserted beyond the anther cone, densely pubescent in the lower third with transparent, tangled simple trichomes; stigma ball-shaped and capitate, bright green in live plants, the surface minutely papillate. Fruit a globose or occasionally slightly ellipsoid berry, 0.8-1 cm in diameter, dark green with white striped mottling when ripe, the pericarp thin, shiny, translucent when ripe, glabrous; fruiting pedicels 1-1.1 cm long, ca. 1 mm in diameter at the base, ca. 1.2 mm in diameter at the apex, somewhat woody, deflexed, usually persistent; fruiting calyx not markedly enlarged, the tube and lobes to ca. 2 mm long, spreading and not markedly appressed to the berry. Seeds 20-30 per berry, 2-2.5 mm long, 1.5-1.7 mm wide, flattened and teardrop shaped, reddish brown, the surfaces minutely pitted, the testal cells sinuate in outline. Stone cells absent. Chromosome number: reported as 2n = 24 ( Edmonds 1972, 1977, voucher Hawkes 'B ', not verified).

Distribution

(Fig. 118 ). Solanum pentlandii occurs in the Andes from central Peru (Depts. Apurimac, Arequipa, Ayacucho, Cusco, Huancavelica, Junín, Lima, Puno, Tacna) to northern Bolivia (Dept. La Paz).

Ecology and habitat.

Solanum pentlandii occurs in open areas at high elevation, often in grassland and along roadsides; it appears to favour high nitrogen environments and is often collected near villages and cities, from 2,400 to 5,200 m elevation.

Common names and uses.

Peru. Cusco: chaja chaja (Iltis & Iltis 867), moyoccaya (Cook & Gilbert 297), qosmayllu (Davis et al. 1348). In the Quechua community of Chinchero (Cusco, Peru), the fruits are macerated and added to water to wash hair in the morning ( Franquemont et al. 1990, as S. arequipense ).

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 190,050 km2 [LC]; AOO = 228 km2 [EN]. Solanum pentlandii has a wide distribution, is a plant of disturbed areas and is common around the protected archaeological sites in the Sacred Valley near Cusco, Peru.

Discussion.

Solanum pentlandii is easy to confuse with S. arequipense and S. furcatum , with which it shares small flowers with short anthers, long-exserted styles and toothed leaf margins. It occurs at generally much higher elevations than either of those taxa, and is usually more glabrous, with shiny, often more deeply and regularly toothed, leaves. Flowers of S. pentlandii are usually dark violet, as compared to the normally white or pale violet flowers of S. arequipense and S. furcatum . The flowers of S. pentlandii are smaller than either of those two species (corolla 0.9 cm in diameter, anthers 2-2.5 mm long and style 5-6 mm long in S. pentlandii ; more than 1.2 cm in diameter, anthers longer than 2.5 mm and style 6-9 mm long in S. arequipense and S. furcatum ).

All of the names we here recognise as synonyms of S. pentlandii were coined by Bitter (1912a) using a number of collections made by Otto Buchtien in Bolivia; no herbaria other than "herb. Boliv." were cited in any of the protologues. We have lectotypified all of these names with specimens from Buchtien’s Herbarium held in US. The lectotype we have selected for S. coerulescens is the more complete of the two sheets of Buchtien 2965 held in US (00027517, acc. # 703363) and is annotated in an unknown hand " S. coerulescens Bitt. n. sp.". Solanum pentlandii var. manophyes and var. Solanum pentlandii pycnophyes are lectotypified with sheets annotated as such by Buchtien (var. Solanum pentlandii pycnophyes - Buchtien 2966, US barcode 00027519, acc. # 1175974; var. Solanum pentlandii manophyes - Buchtien 769 - US barcode 00027518, acc. # 1175829). Another specimen at US of a completely different plant numbered Buchtien 769 (US barcode 00342204, acc. # 1498779) is a specimen of Senna trachypus (Benth.) HS.Irwin & Barnaby ( Leguminosae ; Fabaceae ); Buchtien appears to have used number series multiple times on different collecting trips. Solanum insulae-solis was based on Buchtien s.n. collected on the Isla del Sol in Lago Titicaca (Bolivia); we select as the lectotype here the sheet of Buchtien 5856 at US (barcode 00650475, acc. # 1175976) with the exact collecting locality and date cited by Bitter and annotated "S. insulae-solis Bitt. n. sp." by Buchtien.

Figures

Figure 3. Representative flowers of South American morelloids A campanulate purple corollas in forked internodal inflorescences in S. fiebrigii B pentagonal white corollas in S. annuum C broadly stellate purple corollas with long-exerted styles in S. pentlandii D broadly stellate white corollas with slightly exerted globose stigmas in S. radicans E deeply stellate pale yellow corollas in S. huayavillense F deeply stellate purple corollas with dark central eye colouration in S. salicifolium G bumblebee visiting and buzzing the anther cone in S. cochabambense H variation in corolla shape, size and colouration within a single individual of S. cochabambense (A Barboza et al. 3548 B Barboza et al. 3495 C Knapp et al. 10248 D Knapp et al. 10277 E Barboza et al. 3531 F Chiarini et al. 819 G Saerkinen et al. 4036 H Knapp et al. 10669). Photos by S. Knapp and T. Saerkinen.

Figure 116. Solanum pentlandii A flowering habit B, C fruiting habits D detail of adaxial leaf surface E detail of abaxial leaf surface F flower bud G dissected flower H fruit (A, B, D, F Knapp et al. 10267 C Knapp et al. 10416). Illustration by R. Wise.

Figure 117. Solanum pentlandii A habit B flowering branch C flowers at full anthesis D maturing fruits E fully mature fruits (A, B Knapp et al. 10308 C-E Knapp et al. 10248). Photos by S. Knapp.

Figure 118. Distribution map of Solanum pentlandii.