Solanum pallidum Rusby, Mem. Torrey Bot. Club 4: 228. 1895.

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

36. Solanum pallidum Rusby, Mem. Torrey Bot. Club 4: 228. 1895.

Figs 2F , 110 , 111

Solanum lechleri Rusby, Bull. Torrey Bot. Club 26: 193. 1899. Type. Bolivia. La Paz: Prov. Larecaja, Guanai [Guanay], May 1886, H.H. Rusby 790 (no herbaria cited; lectotype, designated here: NY [00172060]; isolectotypes: GH [00077701], NY [00172059, 00743694], PH [00030433], US [00027648, acc. # 1416231; 01014267, acc. # 32604]).

Solanum lilacinum Rusby, Bull. Torrey Bot. Club 26: 192. 1899. Type. Bolivia. La Paz: Prov. Nor Yungas, Unduavi, Oct 1885, H.H. Rusby 779 (no herbaria cited; lectotype, designated here: NY [00172067]; isolectotypes: BM [BM000778229], NY [00172068, 00172069], US [00027653, acc. # 32597], WIS [v0256196WIS]).

Solanum rosulatum Rusby, Bull. New York Bot. Gard. 4: 418. 1907. Type. Bolivia. Sin. loc., [no date], M. Bang 2518 (no herbaria cited; lectotype, designated here: NY [00172157]; isolectotype: US [00027779, acc. # 1324745]).

Solanum symmetrifolium Rusby, Bull. New York Bot. Gard. 4: 418. 1907. Type. Bolivia. Sin loc., [no date], M. Bang 2870 (no herbaria cited; lectotype, designated here: NY [00172200]; isolectotypes: K [K000585654, K000585655], NY [00172201]).

Solanum sarachioides Rusby, Bull. New York Bot. Gard. 4: 420. 1907, nom illeg., non Solanum sarrachoides Sendtn. (1846). Type. Bolivia. Sin. loc., [no date], M. Bang 2517 (no herbaria cited; lectotype, designated here: NY [00172168]; isolectotype US [00027789, acc. # 1416169]).

Solanum buchtienii Bitter, Repert. Spec. Nov. Regni Veg. 10: 558. 1912. Type. Bolivia. La Paz: Prov. Nor Yungas, Unduavi, 12 Feb 1907, O. Buchtien 765 (no herbaria cited; lectotype, designated here: HBG [HBG-511410]).

Solanum subauriferum Bitter, Repert. Spec. Nov. Regni Veg. 10: 559. 1912. Type. Bolivia. La Paz: Prov. Sud Yungas, Sirupaya prope Yanacachi, 22 Nov 1906, O. Buchtien 332 (lectotype, designated here: US [00027813, acc. # 1175818, as “322”]; isolectotypes: NY [00824366], WRSL).

Solanum scotinonectarium Bitter, Repert. Spec. Nov. Regni Veg. 10: 560. 1912. Type. Bolivia. La Paz: Prov. Sud Yungas, "Sirupay bei Yanacachi", 22 Nov 1906, O. Buchtien 332 (lectotype, designated here: US [00027813, acc. # 1175818]; isolectotype: NY [00824366], WRSL [not seen]).

Solanum planifurcum Bitter, Repert. Spec. Nov. Regni Veg. 11: 2. 1912. Type. Peru. Puno: Prov. Sandia, sin. loc., 2,100-2,500 m, 6 Apr 1902, A. Weberbauer 685 (holotype: B, destroyed [F neg. 2631]; lectotype, designated here: F [v0076175F, acc. # 647966, fragment of holotype).

Solanum sandianum Bitter, Bot. Jahrb. Syst. 50, Beibl. 111: 62. 1913. Type. Peru. Puno: Prov. Sandia, supra Cuyocuyo, 3,800 m, A. Weberbauer 930 (holotype B, destroyed [F. neg. 2636]; no duplicates found); Peru. Puno: Prov. Sandia, km 137 on road from Cuyocuyo to Quiscupunco, 3641 m, 21 Mar 2012, T. Särkinen, A. Mathews & P. Gonzáles 4055 (neotype, designated here: USM [acc. # 00265491]; isoneotypes: BM [BM001120017, BM001120240, BM001120241]).

Type.

Bolivia. Vic. La Paz, M. Bang 64 [a] (no herbaria cited; lectotype, designated here: NY [00172111]; isolectotypes: GH, LE, M [M-0165963], MO [MO-503708, acc. # 1815483], NY [00172112], PH [00030385], US [00027725, acc. # 58341).

Description.

Scandent or lax shrub 1-3 high, with elongate branches. Stems terete, densely pubescent with transparent eglandular dendritic uniseriate trichomes 0.5-1 mm long; new growth densely pubescent with transparent eglandular dendritic uniseriate trichomes 0.5-1 mm long, these drying white or yellowish white in herbarium specimens; bark of older stems greenish brown, somewhat glabrescent. Sympodial units difoliate to plurifoliate, the leaves not geminate. Leaves simple, the blades 2.5-10 cm long, 1-5.2 cm wide, elliptic to ovate-elliptic, widest at the middle or in the lower third, membranous, discolorous; adaxial surfaces moderately and evenly pubescent with transparent dendritic uniseriate trichomes to 0.5 mm long; abaxial surfaces sparsely to densely pubescent with transparent eglandular dendritic uniseriate trichomes to 0.5 mm long, thinner and more delicate than the trichomes of the adaxial surfaces; principal veins 6-8 pairs, often drying yellowish tan; base cuneate to acute; margins entire; apex acute to acuminate; petioles 0.8-1 cm long, adaxially pubescent like the upper leaf surfaces. Inflorescences internodal or terminal at branch tips, forked to several times branched, 3-9(12) cm long, with 20-40 flowers clustered at the branch tips, moderately to densely pubescent with transparent eglandular dendritic uniseriate trichomes to 0.5 mm long like those of the stems; peduncle 1.5-4(6) cm long; pedicels 1-1.5 cm long, ca. 0.75 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, tapering, spreading at anthesis, moderate to densely pubescent with transparent eglandular dendritic uniseriate trichomes to 0.5 mm long, articulated at the base; pedicel scars tightly packed at the ends of the inflorescence branches, 1-1.5 mm apart. Buds ellipsoid, the corolla strongly exserted from the calyx before anthesis, usually darker than the corolla in flower. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1.5-2 mm long, conical, the lobes 1.5-2.5 mm long, ca. 1 mm wide, triangular, sometimes somewhat reflexed at anthesis, moderately pubescent with transparent eglandular dendritic trichomes to 0.5 mm long, like those of the pedicels. Corolla 2-2.3 cm in diameter, pale to dark purple with a green eye, stellate, lobed ca. halfway to the base, the lobes 6-9 mm long, 4-6 mm wide, deltate, spreading at anthesis, adaxially glabrous except for the papillate lobe tips, abaxially puberulent with white eglandular simple and dendritic trichomes where exposed in bud, these denser on the midveins and tips, the interpetalar tissue more glabrous. Stamens equal; filament tube minute to 0.1 mm long; free portion of the filaments 1-1.5 mm long, very densely pubescent adaxially with tangled simple uniseriate trichomes. Ovary conical, glabrous; style 6-8 mm long, straight, exserted beyond the anther cone, densely pubescent in the lower part with transparent simple uniseriate trichomes to 0.5 mm long; stigma small-capitate, the surfaces minutely papillate. Fruit a globose berry, 0.8-1 cm in diameter, green when immature, ripening to blackish purple, the pericarp thin, matte, opaque, glabrous; fruiting pedicels 1.3-1.4 cm long, ca. 1.2 mm in diameter at the base and apex, not markedly woody, deflexed, not persistent; fruiting calyx not markedly accrescent, the lobes to 4 mm long and slightly reflexed at the tips, the tube appressed to the berry. Seeds ca. 20 per berry, ca. 2 mm long, ca. 1.5 mm wide, flattened and teardrop shaped, reddish gold, the surfaces minutely pitted, the testal cells sinuate in outline. Stone cells 6 per berry, scattered through the mesocarp, ca. 1 mm in diameter, cream-coloured, two of the inclusions slightly smaller. Chromosome number: 2n = 24 ( Chiarini et al. 2017, voucher Särkinen et al. 4014).

Distribution

(Fig. 112 ). Solanum pallidum occurs from south-central Peru (Depts. Huánuco, Ayacucho, Cusco, Puno) to northern Bolivia (Depts. Cochabamba, La Paz) on the eastern Andean slopes.

Ecology and habitat.

Solanum pallidum grows in cloud forests, cloud forest edges and clearings, roadsides and montane scrub, from (600-)1,200 to 4,000 m elevation. Most specimens have been collected between 2,000 and 2,800 m elevation.

Common names and uses.

Peru. Cusco: muyuqhaya ( Särkinen et al. 5284). No uses recorded.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 140,455 km2 [LC]; AOO = 340 km2 [EN]. Solanum pallidum is a weedy shrub of landslides and road edges and has a relatively wide distribution; it occurs around many of the protected archaeological sites in the region of Cusco, Peru.

Discussion.

Solanum pallidum is morphologically similar to S. cochabambense in its large flowers and highly branched inflorescences usually on long peduncles but is easily distinguished from it by often dense pubescence composed of branched (dendritic) trichomes on all plant parts. The two taxa are somewhat sympatric, but S. pallidum is confined to the eastern Andean slopes, while S. cochabambense occurs on both slopes of the Andes in Peru. Molecular sequence data suggest the species are closely related ( Gagnon et al. 2022).

The collection used to describe S. pallidum (Bang 64; Rusby 1895) is a mixed gathering of S. pallidum and S. gonocladum (see S. gonocladum ). We have selected the sheet at NY (barcode 00172111) that has the protologue attached and is annotated by Rusby as the lectotype for S. pallidum . Care must be taken with assigned duplicates of Bang 64 as isolectotypes, some sheets correspond to S. bangii , a synonym of S. gonocladum .

In subsequent years Rusby (1899, 1907) described several names we here recognise as synonyms of S. pallidum but cited no herbaria in the protologues We have lectotypified all of these with the specimens in NY (where the specimens that Rusby used are held) that best correspond to the protologues and are most complete (see above).

Bitter (1912a) described S. buchtienii citing Buchtien 765 with the date of 12 Feb 1907 but no herbarium; of the duplicates we have seen, only that in HBG (HBG-511410) has that number and the correct date; we designate it here as the lectotype. Other collections (e.g., NY barcode 00139077 and US barcode 00027486, acc. # 700088) do not have the same collecting date (date of collection Nov 1910) and so are not part of the same gathering and thus are not isolectotypes. In the same publication Bitter described S. scotinonectarium citing Bang 31 pro parte from "herb. Berol." and Buchtien 332 pro parte from "herb. Buchtien! Vratisl.!". He often used different duplicates of the same collection to describe different taxa based on minor leaf shape and size differences; he also cited Buchtien 332 pro parte as the basis for S. subauriferum without citing a herbarium but saying "una cum S. scotinonectarium ". Bang 31 at "herb. Berol" also forms the basis for his S. irenaeum ( Bitter 1912a), a synonym of S. polytrichostylum . A sheet in US (barcode 00027813, acc. # 1175818) bears both the numbers 322 and 332 and is annotated " S. subauriferum Bitt. n. sp." by Buchtien; we are interpreting the number 322 as an error to be corrected. In view of Bitter’s practice of using different sheets of the same gathering to describe different species, the destruction of the WRSL sheet of Buchtien 332 and the Buchtien Herbarium being held at US ( Morton and Stern 1966), we have designated the US sheet as the lectotype of both S. scotinonectarium and S. subauriferum making these names homotypic.

Solanum sandianum was described ( Bitter 1913) citing a collection made by August Weberbauer in southern Peru (Weberbauer 930) held in Berlin (F. neg. 2636). That specimen is destroyed and we have found no duplicates, even at MOL where Weberbauer’s original herbarium is held. We thus neotypify this name with a modern collection made near the type locality of Cuyocuyo in Sandia Province ( Särkinen et al. 4055) held in the Peruvian National Herbarium (USM).

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 110. Solanum pallidum A habit B habit with larger leaves C detail of adaxial leaf surface D detail of abaxial leaf surface E flower bud F dissected flower G fruit (A, C-G Knapp et al. 10445 B Knapp et al. 10444). Illustration by R. Wise.

Figure 111. Solanum pallidum A habit B flower buds with dense indumentum of dendritic trichomes C flowers at full anthesis D maturing fruits (A Saerkinen et al. 4010 B Knapp et al. 10433 C Saerkinen et al. 4042 D Saerkinen et al. 4010). Photos by S. Knapp and T. Saerkinen.

Figure 112. Distribution map of Solanum pallidum.