Solanum paucidens Bitter, Repert. Spec. Nov. Regni Veg. 11: 226. 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

37. Solanum paucidens Bitter, Repert. Spec. Nov. Regni Veg. 11: 226. 1912.

Figs 113 , 114

Solanum diffusum Vell., Fl. Flumin. 83. 1829 [1825], nom.illeg., non Solanum diffusum Ruiz & Pav. (1799). Type. Brazil. [Rio de Janeiro]: "campis apricis mediterraneis"; (lectotype, designated by Knapp et al. 2015, pg. 829: [illustration] Original parchment plate of Flora Fluminensis in the Manuscript Section of the Biblioteca Nacional, Rio de Janeiro [cat. no.: mss1198651_101] and later published in Vellozo, Fl. Flumin. Icon. 2: tab. 98. 1831).

Solanum maracayuense Bitter, Repert. Spec. Nov. Regni Veg. 11: 227. 1912. Type. Paraguay. Canindeyú: "Sierra de Maracayú”, Nov, É. Hassler 5278 (holotype: B, destroyed; lectotype, designated here: G [G00306843]; isolectotypes: BM [BM000074095], G [G00306845], GH [00105865], K [K000532494], NY [00172082], P[P00753766, P00753765, P00337048], UC [950199])

Solanum rojasii Chodat, Bull. Soc. Bot. Genève, sér. 2, 8: 150. 1916. Type. Paraguay. Paraguarí: [Cerro] Acahay, R. Chodat & W. Vischer 67 (lectotype, designated here: G [G00449278]; isolectotype: G [G00449243]).

Solanum maioranthum L.B.Sm. & Downs, Phytologia 10: 425. 1964. Type. Brazil. Santa Catarina: Rio do Rastro, 20 km west of Lauro Müller, lower and middle slopes of Rio do Rastro, L.B. Smith & R.M. Klein 12338 (holotype: US [00067554, acc. # 2423800]; isotypes: K [K000590017], NY [00172074], R [R000129993], US [03272136, acc. # 2492258]).

Type.

Brazil. Rio de Janeiro: Theresopolis, Nov-Dec 1888, J.T. de Moura 578 (holotype: B, destroyed [F neg. 2839]; lectotype, designated here: F [v0073360F, acc. # 621340, fragment of holotype]) .

Description.

Herb to small subshrub with lax branches, 0.5-1.5 m high. Stems terete or slightly angled, sparsely pubescent with white eglandular 3-5-celled simple uniseriate trichomes ca. 0.5 mm long, also with a few spinescent processes along the angles; new growth densely white pubescent with eglandular 3-7-celled simple uniseriate trichomes ca. 0.5 mm long, these usually antrorse; bark of older stems pale greenish grey. Sympodial units difoliate, the leaves not geminate. Leaves simple or shallowly toothed, the blades 2-9(15) cm long, 1.5-3(5) cm wide, narrowly elliptic, widest at the middle or in the lower half, membranous, concolorous or slightly discolorous, very variable in size with lower leaves much larger; adaxial surfaces almost glabrous, with a few scattered white eglandular simple uniseriate trichomes ca. 0.5 mm long on the lamina, these somewhat denser along the veins; abaxial surfaces moderately and evenly pubescent with similar white eglandular simple uniseriate trichomes ca. 0.5 mm long; principal veins 4-6 pairs, more densely pubescent than the lamina; base acute; margins entire or with a few irregular teeth in the lower half; apex acute; petiole 0.5-0.9 cm long, pubescent with scattered white eglandular trichomes like those of the stem. Inflorescences internodal, unbranched or forked, 1.5-2.5 cm long, with 5-10 flowers not markedly clustered at the tips, moderately to sparsely pubescent with white eglandular simple uniseriate trichomes like those of the stems; peduncle 1.2-2.3 cm long; pedicels 0.6-0.7 cm long, 0.4-0.5 mm in diameter at the base, 1-1.2 mm in diameter at the apex, spreading or slightly deflexed and secund at anthesis, sparsely to moderately pubescent like the inflorescence axes, articulated at the base; pedicel scars more or less evenly spaced 0.5-1 mm apart along the axis, somewhat raised from the axis as small protuberances. Buds narrowly 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 0.5-1 mm long, 0.5-1 mm wide, deltate to broadly triangular, often tearing irregularly, sparsely pubescent with white eglandular simple uniseriate trichomes like the inflorescence, but these sparser than on the pedicel. Corolla 0.8-1.2 cm in diameter, white with a central green star, lobed 2/3 to 3/4 of the way to the base, the lobes 3-4 mm long, 1.5-1.7 mm wide, spreading or reflexed at anthesis, glabrous adaxially, sparsely and evenly puberulent-papillate, more densely so on the tips and margins. Stamens equal; filament tube minute; free portion of the filaments 1-1.5 mm long, densely pubescent adaxially with tangled simple uniseriate trichomes; anthers 2.5-3.5 mm long, ca. 1 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary conical, glabrous; style 8-9 mm long, straight, exserted beyond the anther cone, densely pubescent with white simple uniseriate trichomes ca. 0.5 mm long in the lower half; stigma capitate, the surfaces minutely papillate. Fruit a globose berry, 0.8-1 cm in diameter, black or purple when ripe, the pericarp thin, somewhat shiny, translucent, glabrous; fruiting pedicels 0.7-1 cm long, ca. 0.7 mm in diameter at the base, ca. 1.2 mm at the apex, gradually tapering, not markedly woody, strongly deflexed at the base and the infructescence appearing secund in herbarium specimens, not persistent; fruiting calyx not enlarged or accrescent, appressed to the berry, the lobes tearing to become ca. 2 mm long. Seeds 40-80 per berry, 1.3-1.5 mm long, 1-1.2 mm wide, flattened and teardrop shaped, pale tan or yellow, the surfaces minutely pitted, the testal cells rectangular to slightly sinuate in outline, with short hair-like extensions of the lateral cell walls. Stone cells 2-6(8) per berry, 0.5-0.7 mm in diameter, cream-coloured. Chromosome number: not known.

Distribution

(Fig. 115 ). Solanum paucidens occurs in southern Brazil (States of Espírito Santo, Mato Grosso, Minas Gerais, Paraná, Rio de Janeiro, Rio Grande do Sul, São Paulo, Santa Catarina), northeastern Argentina (Provs. Corrientes, Misiones) and eastern Paraguay (Depts. Alto Paraná, Central, Guairá).

Ecology and habitat.

Solanum paucidens is a plant of middle to low elevations in the semideciduous and evergreen Mata Atlântica and Selva Paranense, growing in swampy areas, forest edges and clearings and forest understory, from near sea level to 2,000 m in the Atlantic forest mountains.

Common names and uses.

Brazil. Minas Gerais: erva-moura (Souza et al. s.n.), erva nome (Andrade 1209). Uses and common names attributed to S. americanum in Lorenzi and Abreu Matos (2021) and Ferreira Kinupp and Lorenzi (2022) may also apply to S. paucidens , although the photographs appear to be in large part S. americanum ; there are no vouchers cited.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 1,233,243 km2 [LC]; AOO = 196 km2 [EN]. Solanum paucidens has a broad geographical distribution and is a weedy species of open areas and roadsides where it occurs. It occurs within protected areas in Argentina (e.g., Reserva Vida Silvestre Urugua-í in Misiones) and Brazil (e.g., Parque Nacional Itatiaia at the border of Minas Gerais, São Paulo and Rio de Janeiro, Parque Estadual Intervales in Santa Catarina, Parque Estadual Ibtipoca in Minas Gerais).

Discussion.

The name S. paucidens has not been in common use for this species, in part due to the poor quality of the type specimen (see below). Earlier treatments either treated this species as new (e.g., Smith and Downs 1966 as S. maioranthum ) or as S. nigrescens (e.g., Mentz and Oliveira 2004), a species from North, Central and northern South America. The flowers of S. paucidens are usually evenly spaced along the elongate inflorescence axis, in contrast to S. nigrescens where they are clustered at the tip or not widely spaced. Solanum paucidens is most similar to S. enantiophyllanthum , with which it is nearly sympatric in the mountain ranges of southern Brazil. Solanum paucidens has smaller flowers (0.8-1.2 cm in diameter versus 1.9-2 cm in diameter) with shorter anthers (2.5-3.5 mm long versus 4.5-6 mm long) than S. enantiophyllanthum and grows at somewhat lower elevations where their distributions overlap. In herbarium specimens the inflorescences of S. paucidens appear secund, with flowers and fruits on one side of the inflorescence axis; this is most easily seen in fruiting specimens.

Bitter (1912b) described S. paucidens citing only a collection by “Julio” Moura (referring to Julia T. de Moura) from a specimen in the Berlin Herbarium. That specimen no longer exists, and we have looked for duplicates in other herbaria where collections might be found (e.g., BR), but have been unsuccessful. The fragment of the holotype at F mounted on the sheet with the photograph (F neg. 2839) taken by J.F. Macbride in Berlin (barcode v0073360F, acc. # 621340) is more or less adequate for identification and is here designated as the lectotype. Further duplicates of this gathering may be found at R that are better representations of the species, thus we do not at this stage designate an epitype.

In describing S. maracayuense Bitter (1912b) cited Hassler 5278 from Berlin, but this specimen is no longer extant. Two sheets of Hassler 5278 are held in the Hassler Herbarium at G, and we select the better of these with flowers and fruits (G00306843) as the lectotype for this name.

Chodat (1916) cited Chodat & Visscher 67 from "herb. Univ. de Geneve" in the protologue of S. rojasii . This herbarium is now held at G, and we have selected the more complete of the two duplicates (G00449278) held there that is labelled “holotype” as the lectotype for S. rojasii .

Figures

Figure 113. Solanum paucidens A habit B portion of a leaf, abaxial surface C flower D dissected flower E gynoecium F infructescence G fruit H seed I stone cell (A-I Gomes s. n.). Illustration by S. Montecchiesi.

Figure 114. Solanum paucidens A habit B inflorescence C maturing fruits (A-C Smith & Klein 12338 [GH 01011894]). Reproduced with permission of the Gray Herbarium, Harvard University.

Figure 115. Distribution map of Solanum paucidens.