Solanum chmielewskii
Citation:
Amer. J. Bot. 80: 683. 1993.
Type:
Based on Lycopersicon chmielewskii C.M. Rick, Kesicki, Fobes & Holle.
Written by:
Peralta, I.E., S. Knapp & D.M. Spooner
Habit:
Trailing or spreading perennial herbs, woody at the base, to 1 m tall, to 1 m or more in diameter. Stems 0.4-0.5 cm in diameter, pale grayish green, densely velvety pubescent with soft white, simple, uniseriate trichomes to 0.2 mm long from a unicellular base, these interspersed with longer uniseriate 3-4-celled trichomes from multicellular bases and tiny glandular trichomes with 4-celled glands (less often the glands 1 or 8-celled), the glandular trichomes more abundant on the young growth.
Sympodial structure:
Sympodial units 2-foliate; internodes 3-8 cm long.
Leaves:
Leaves interrupted imparipinnate, 5-12 cm long, 2-6 cm wide, dark green to pale green beneath, adaxially soft velvety pubescent with simple, uniseriate eglandular trichomes like those of the stems, occasionally with longer more robust trichomes from a darker, multicellular base, abaxially the pubescence similar but denser, evenly spread on the veins and the lamina, the abaxial surface paler due to more abundant pubescence; primary leaflets 2-3 pairs, the basal pair usually smaller, narrowly elliptic to elliptic, the base truncate, very oblique and decurrent basiscopically, the margins entire to deeply crenate, the crenations deeper near the base of the leaflets, the apex acute; terminal leaflet the same size or often larger than than the laterals, (1.5-) 2-4.8 cm long, (0.5-) 0.6-1.8 cm wide, the apex long acuminate, the petiolule 0.2-1 cm long, the apex acute; lateral leaflets (0.5-) 1-3.4 cm long, (0.3-) 0.4-1.5 cm wide, sessile or the petiolule to 0.5 cm long; secondary leaflets absent; tertiary leaflets absent; interjected leaflets 0-4, 0.1-0.9 cm long, 0.1-0.7 cm wide, sessile; petiole 1-3 cm long; pseudostipules present on some nodes, 0.5-1 cm long, 0.4-0.8 cm wide, the margin entire to irregularly crenate.
Inflorescences:
Inflorescences (2-) 3-9 cm, simple or sometimes once branched, with 2-7 (-15) flowers, with bracts on the basal nodes, the bracts 0.3-0.7 cm long, 0.4-0.5 cm wide, peduncle (1-) 2-4 (-11) cm long, pubescent like the stems. Pedicels 0.7-1 cm long, articulated in the distal half. Buds 1-1.2 cm long, ca. 0.5 cm wide, conical, with the corolla only halfway exserted from the calyx lobes just before anthesis.
Flowers:
Flowers with the calyx tube 0.05-0.1 cm long, the lobes 0.5-0.7 cm long, 0.15-0.2 cm wide, lanceolate, sparsely to densely pubescent with small simple, uniseriate trichomes and a few glandular trichomes like those of the inflorescence axis; corolla 1.6-2 cm in diameter, rotate-stellate, bright yellow, the tube 0.3-0.5 cm long, the lobes 0.5-0.8 cm long, reflexed at anthesis; staminal column 0.9-1.1 cm long, straight, the filaments ca. 0.5 mm long, the anthers 0.6-0.7 cm long, the sterile apical appendage 0.15-0.2 cm long; ovary globose, or minutely papillate at the apex; style 0.8-0.9 cm long, ca. 0.5 mm in diameter, densely white pubescent in the basal half, straight, exserted 0.5-1 mm beyond the sterile appendage; stigma minutely capitate, green.
Fruits:
Fruit 1-1.3 cm in diameter, globose, 2-locular, green, with a dark green stripe from the apex to the base, densely papillate and sparsely pubescent with extremely slender and weak simple uniseriate trichomes to 0.5 mm long; fruiting pedicels 1-1.3 cm long, straight or slightly angled at the articulation; calyx lobes in fruit 0.8-1 cm long, 0.2-0.3 cm wide, loosely investing the base of the berry to somewhat spreading.
Seeds:
Seeds 2.2-3.2 mm long, 1.2-1.6 mm wide, 0.6-0.8 mm thick, obovate, pale brown, pubescent with hair-like outgrowths of the lateral testa cell walls, these adpressed and giving a silky appearance to the surface, narrowly winged (ca. 0.2 mm) at the apex and acute at the base.
Distribution:
In high dry Andean valleys from the Department of Apurimac in southern Peru to Sorata in northern Bolivia, from 2300-3000 m elevation.
Phenology:
Solanum chmielewskii flowers from December to April, but it is likely that flowering occurs sporadically throughout the year (Rick et al. 1976).
Phylogeny:
Solanum chmielewskii is a member of the Potato clade (sensu Weese & Bohs, 2007); within the tomatoes and wild relatives it is a member of the “Arcanum group” and is a member of section Lycopersicon.
References:
Rick, C.M., E. Kesicki, J.F. Fobes, & M. Holle 1976. Genetic and biosystematic studies on two new sibling species of Lycopersicon from Interandean Perú.
Theor. Appl. Genet. 47: 55-68.
Solanum chmielewskii is sister to S. neorickii, and is difficult to distinguish from that species in the absence of flowers. Both species are related to S. arcanum, from northern Peru, rather than to S. lycopersicum and the other red-fruited species as was suggested by Rick et al. (1976). The flowers of S. chmielewskii are about twice the size of those of S. neorickii and the stigma is always exserted from the anther cone. The corolla tube tends to be slightly larger in diameter, with a more pentagonal corolla outline. Both species have uniform, short whitish pubescence, and small green fruits. Rick et al. (1976) suggested that the outcrossing S. chmielewskii gave rise to the autogamous S. neorickii in their area of sympatry in southern Peru (Dept. Apurimac), near the type localities for both species. Crosses between the two species usually resulted in low seed set (Rick et al. 1976), suggesting they have developed reproductive isolation, at least in their area of sympatry. Hybrids obtained were intermediate in size between the two parents. Solanum chmielewskii prefers drier, better-drained habitats than S. neorickii (Rick et al. 1976) and is found at somewhat higher elevations. The only Bolivian collection is from the Sorata Valley (Mandon 392) which is drier than other yungas valleys in Bolivia, and is the southern limit for other Solanaceae of dry habitats, such as Nicotiana glutinosa L.