Solanum macrotonum Bitter, Repert. Spec. Nov. Regni Veg. 11: 222. 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

30. Solanum macrotonum Bitter, Repert. Spec. Nov. Regni Veg. 11: 222. 1912.

Figs 92 , 93

Solanum frutescens A.Braun & C.D. Bouché, Ind. Sem. Hort. Berol. App. 9. 1853, nom. utique rej. Type. Cultivated at Berlin Botanical Garden from seed sent from Caracas, Venezuela by J.W.K. Moritz, Anon. s.n. (possibly described from living material; if type material at B, destroyed; Knapp et al. 2018; Applequist 2022).

Solanum megalophyllum Bitter, Repert. Spec. Nov. Regni Veg. 11: 202. 1912. Type. Cultivated in England (?) ex Herb. A.B. Lambert "Villa Caracas cultum in hort. Boyton, Ph. Woodford", Anon. s.n. (lectotype, designated by Knapp et al. 2019, pg. 75: W [acc. # 1889-0291427]; isolectotype: W [acc. # 1889-0291426 = F neg. 33091]).

Solanum diodontum Bitter, Repert. Spec. Nov. Regni Veg. 12: 552. 1913. Type. Panama. Chiriqui: around El Potrero Camp, 2,800-3,000 m, 10-13 Mar 1911, H. Pittier 3104 (holotype: US [US00027551, acc. # 677494]; isotype: GH [GH00077485], NY [NY00138980], US [US00027550, acc. # 1405957]).

Solanum leonii Heiser, Ceiba 4: 298. 1955. Type. Costa Rica. Cartago: near Robert, Irazú [protologue -wooded ravine 1/2 mile below Finca Robert], 8,500 ft., 4 Oct 1953, C.B. Heiser 3597 (holotype [two sheets]: IND [sheet 1, IND-0136009, acc. # 95138; sheet 2, IND-00136010, acc. # 95137]; isotype: F [V0073111F, acc. # 143245 = F neg. 49431]).

Solanum paredesii Heiser, Ci. & Naturaleza [Quito] 6: 55. 1963. Type. Ecuador. Pichincha: [ Cantón Quito] laderas al norte de los terrenos de la Universidad Central, Ciudad Universitaria Quito, 24 May 1962, C.B. Heiser 5001 (holotype: IND [IND-0136006, acc. # 106787]; isotype: Q [n.v.]).

Type.

Venezuela. Aragua: Colonia Tovar , Sep 1847, J.W.K. Moritz 1643 (holotype: B, destroyed [F neg 2669]; lectotype, designated by D’Arcy 1974a, pg. 737: P [P00336967]; isolectotypes: BM [BM000617678], F [v0073325F, acc. # 612111], HBG [HBG511459], K [K000585559]) .

Description.

Perennial herbs to subwoody shrubs, 0.7-2 m high, perhaps occasionally annual or only persisting for a few years, often described as “viney”. Stems terete or angled with spinose processes, arching and scrambling over other vegetation, often drying blackish grey; young stems densely pubescent with somewhat antrorse, simple uniseriate eglandular trichomes 0.5-1 mm long, the trichomes drying white, soon glabrescent; new growth densely white pubescent like the young stems, glabrescent; bark of older stems green to greenish brown. Sympodial units difoliate or unifoliate, the leaves not geminate. Leaves simple, occasionally with a few dentate teeth near the base, the blades (2)4-10(12) cm long, (0.8)1.8-4.5(5.5) cm wide, elliptic to narrowly obovate, widest at the middle or in the upper half, sometimes thick (described as succulent), but more often membranous, concolorous; adaxial surfaces sparsely pubescent with simple 3-4-celled uniseriate trichomes or almost glabrous, the trichomes denser on veins and midrib; abaxial surfaces sparsely pubescent to glabrous like the adaxial surfaces, but the trichomes denser along the veins; principal veins 5-7 pairs, drying paler abaxially; base abruptly attenuate along the petiole; margins entire to sparsely toothed near the base; apex acute to narrowly acute; petiole 0.5-2.5 cm, sparsely pubescent with antrorse simple uniseriate trichomes like those of the stems and leaves. Inflorescences internodal or very occasionally opposite the leaves, unbranched or very occasionally forked (e.g., Ruíz-Teran 14155), 0.7-4 cm long, with 2-3(7) flowers clustered in the distal part of the axis (sub-umbelliform), sparsely pubescent with simple uniseriate trichomes like those of the stems and leaves; peduncle 0.5-4 cm long; pedicels 1-1.3 cm long, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter at the apex, tapering gradually and appearing relatively stout, often described as reddish purple or purple, spreading at anthesis, sparsely pubescent or glabrous, articulated at the base; pedicel scars tightly packed in the distal portion of the inflorescence, less than 0.5 mm apart or occasionally the lowermost scar to 2 mm apart. Buds broadly ellipsoid to subglobose, the corolla long-exserted from the calyx tube before anthesis. Flowers 5-merous, cosexual (hermaphroditic). Calyx tube 1-1.5 mm long, conical, the lobes 0.5-0.8(1) mm long, 0.5-1 mm wide, broadly deltate with acute apices, sparsely pubescent with simple uniseriate trichomes like those of the pedicel or almost glabrous. Corolla 1-2 cm in diameter, white to lilac or tinged with lilac, the central portion yellowish green, stellate, lobed halfway to 2/3 of the way to the base, the lobes 4-6 mm long, 1.5-3 mm wide, triangular, reflexed or spreading at anthesis, abaxially sparsely puberulent with tiny simple uniseriate trichomes. Stamens equal; filament tube minute and barely visible, the free portion of the filaments 1-2 mm long, pubescent with tangled simple uniseriate trichomes adaxially; anthers (2.7)3-4 mm long, 1-1.5 mm wide, ellipsoid, bright yellow, the surfaces smooth, poricidal at the tips, the pores elongating to slits with age. Ovary glabrous; style 5-6 mm long, straight, exserted beyond the anther cone, densely pubescent with tangled simple uniseriate trichomes in the basal half where included in the anther cone, markedly exserted from the anther cone; stigma capitate or minutely capitate, bright green, the surface densely papillate. Fruit a globose berry, 0.8-1 cm in diameter, green turning to black when ripe or occasionally green when ripe (Nee & Whalen 16839), the pericarp thin, more or less shiny but not brilliantly so, opaque, glabrous; fruiting pedicels 15-17 mm long, tapering from a base 0.7-1 mm in diameter to an apex 1.5-2 cm in diameter, somewhat woody, strongly deflexed (very occasionally appearing spreading due to herbarium specimen preparation), not persistent or occasionally remaining on the inflorescence axis; fruiting calyx not accrescent, the tube 1-1.5(2) cm long, appressed to the berry, the lobes 0.5-1 mm long, appressed or spreading at the tips. Seeds (10)30-50 per berry, 1.2-1.5 mm long, 0.8-1 mm wide, flattened and teardrop shaped, tan to reddish brown, the surfaces minutely pitted, the testal cells pentagonal, more elongate and rectangular near the hilum. Stone cells (2)4-5(6) per berry, 0.5-0.7 mm in diameter, white or cream-coloured. Chromosome number: 2n = 24 ( Heiser 1955, as S. leonii ); n = 36 ( Heiser 1963, as. S. paredesii ).

Distribution

(Fig. 94 ). Solanum macrotonum is widely distributed from Guatemala to northern South America; Colombia (Depts. Antioquia, Boyacá, Cauca, Cundinamarca, Huila, Magdalena, Meta, Nariño, Norte de Santander, Putumayo, Quindío, Risaralda, Santander, Tolima, Valle de Cauca), Ecuador (Provs. Azuay, Bolívar, Carchi, Chimborazo, Cotopaxi, Imbabura, Loja, Morona-Santiago, Napo, Pichincha, Sucumbios, Tungurahua, Zamora-Chinchipe), Venezuela (States of Aragua, Lara, Mérida, Miranda, Sucre, Táchira, Trujillo, Vargas) and in the Antilles on the islands of Hispaniola and Jamaica.

Ecology and habitat.

Solanum macrotonum is a plant of open areas in cloud forests and premontane and montane forests, occurring in treefall gaps and along roads and other disturbances, from (200-)1,000 to 3,400 m elevation.

Common names and uses.

Colombia. Antioquia: hierba mora (Kirkbride & Forero 1853); Pasta: yerba mora (Vogelmann 2006); Cundinamarca: yerba mora ( Barragán-Fonseca 9); Santander: yerba mora (Combita et al. 114). Ecuador. Chimborazo: hierba mora ( Cerón 15905 [a]); Napo: hierba mora macho (Baez et al. 32B); Pichincha: papa de monte (Mena V. 123). Venezuela: Vargas: yerba mora ( González 17). In Ecuador (Chimborazo, Ceròn 15905 [a]) an infusion of leaves is used as a bath for medicinal purposes.

Preliminary conservation status

( IUCN 2022). Least Concern [LC]. EOO = 4,218,133 km2 [LC]; AOO = 936 km2 [EN]; calculated on entire range in the Americas. Solanum macrotonum is widespread and is a weedy plant throughout its range. It occurs in several protected areas in Colombia (e.g., Selva de las Ventanas Natural Reserve), Ecuador (e.g., Bosque Protector de Pasochoa, Parque Nacional Llanganates) and Venezuela (e.g., Parque Nacional Chorro del Indio).

Discussion.

Solanum macrotonum is broadly sympatric with S. nigrescens across its entire range (see Knapp et al. 2019). It is similar to S. nigrescens in having usually 4 to 5 stone cells per berry and black fruits that are more or less shiny. It can be distinguished from S. nigrescens in having longer anthers (to 4 mm rather than to 2.5 mm) and in having more robust, longer fruiting pedicels that are strongly deflexed. Many annotations in herbaria have been done based on elevation (see comments in Bohs 2015) so care must be taken with determinations of these species. Measurement of anthers is the best way to determine specimens unambiguously. In general, S. macrotonum does occupy slightly higher elevations than does S. nigrescens , and appears to be confined to cloud forests, but S. nigrescens has a wide elevational range and ecological tolerance. The two species are sympatric throughout northern South America (Colombia and Venezuela).

Solanum macrotonum is also morphologically similar to S. longifilamentum , but as with S. nigrescens , differs from it in its longer anthers. Solanum macrotonum has larger corollas (1-2 cm in diameter versus 0.5-0.6 cm in diameter in S. nigrescens ) and broadly deltate (rather than triangular) calyx lobes that do not split at the sinuses. The strongly deflexed fruiting pedicels of S. macrotonum are distinct from the spreading ones of S. longifilamentum .

Solanum macrotonum is one of few morelloids with differing chromosome counts across its range (but see also S. interandinum ). D’Arcy (1974a) reported a chromosome number of "n = 36" for S. macrotonum as a personal communication from J.M. Edmonds; the chromosome count in Edmonds (1972) is not new and we presume it is a reference to the count ( “número de cromosomas - 36"; Heiser 1963) given in the protologue of S. paredesii , which Edmonds (1972) placed in tentative synonymy with S. macrotonum . Some other chromosome vouchers of S. macrotonum at IND, however (e.g., Heiser 4854) are noted as having "n = 24" on the label; Heiser (1963) did not cite these in the description of S. paredesii . Chromosome counts for S. leonii , here treated in synonymy with S. macrotonum , indicate it is diploid, with 2n = 24 ( Heiser 1955). Chromosome number variation within a species is known in Solanum (e.g., in the potatoes, see Spooner et al. 2014), and sometimes occurs sporadically at the edges of species ranges. It will be important to assess this across the range of S. macrotonum , because we cannot find any morphological characteristic that distinguishes vouchers with different chromosome counts.

Details of the typification of S. macrotonum and its synonyms can be found in Knapp et al. (2019). The earlier name S. frutescens A.Braun & C.D. Bouché was proposed ( Knapp et al. 2018) and recommended for suppression ( Applequist 2022).

Figures

Figure 92. Solanum macrotonum A fertile branch with flower buds and fruits B flowering and fruiting branch C stem detail with eglandular multi-cellular trichomes D flower bud E flower at full anthesis F dissected flower G infructescence H fruit I seed (A-C, G-I Ezedin & Saerkinen 48; D-F Balls 7528). Illustration by C. Banks.

Figure 93. Solanum macrotonum A habit B inflorescence C flower at full anthesis D maturing fruits (A-D Ezedin & Saerkinen 48). Photos by T. Saerkinen. Previously published in Knapp et al. (2019: 77).

Figure 94. Distribution map of Solanum macrotonum in South America. For distribution in North and Central America and the Caribbean, see Knapp et al. (2019: 78).