stage missing = ploidy missing = chrom_num missing = voucher missing =
Northwestern Argentina (Depts. Tucumán, Salta, Jujuy), Bolivia, southern Peru (Dept. Cuzco), at 1200–4750 m, rarely down to 800 m.
Solanum palitans belongs to a clade of four closely related Andean species; the other members of this clade are S. tripartitum, S. corymbosum, and S. radicans. This clade of four species is sister to a clade containing members of Solanum section Solanum within the Morelloid clade (sensu Bohs, 2005) of the non-spiny Solanums and was placed in a broadly defined sect. Dulcamara by Nee (1999). Sequence data from the nuclear waxy and chloroplast trnT-F regions indicate that within this clade S. palitans is most closely related to S. tripartitum. The two species are sympatric and will apparently hybridize in the field (see Commentary).
Morton, C.V. 1976. A revision of the Argentine species of Solanum.
Pp. 1-260. Academia Nacional de Ciencias, Córdoba, Argentina.
Nee, M. 1999. Synopsis of Solanum in the New World.
Pp. 285–333 in M. Nee, D. E. Symon, R. N. Lester & J. P. Jessop (eds.), Solanaceae IV: Advances in Biology and Utilization. Royal Botanic Gardens, Kew.
Bohs, L. 2005. Major clades in Solanum based on ndhF sequences.
Pp. 27-49 in R. C. Keating, V. C. Hollowell, & T. B. Croat (eds.), A festschrift for William G. D’Arcy: the legacy of a taxonomist. Monographs in Systematic Botany from the Missouri Botanical Garden, Vol. 104. Missouri Botanical Garden Press, St. Louis.
Solanum palitans is very easily confused in the herbarium with the sympatric S. tripartitum Dunal, and the species are mixed under the same collection number in several cases. In the field they are easily distinct, but even here it is easy to confuse them (but see key below) and there are apparently hybrids, at least in Bolivia. In Achumani, a suburb of the city of La Paz, Bolivia, forty individual plants were selected more at less at random from an area of ruderal vegetation on dry rocky slopes and gravelly stream beds; 25 proved to be S. tripartitum (Nee 32057a–y), 11 were S. palitans (Nee 32058a–k), and 4 seemed to be intermediate (Nee 32058a–d). The plants of Nee 32058a–d were similar to S. palitans, but had the branched inflorescences of S. tripartitum. Another possible hybrid was from Dpto. La Paz, Prov. Murillo, Valencia, 2 km NW of Mecapaca, in the arid valley of Río La Paz, 16°39’S, 68°02’W, 2950 m, 15 Feb 1987 (fl,fr), Nee & Solomon 34175 (LPB, NY).
Poorly prepared herbarium specimens and those in young flowering condition can be difficult to identify; mixed collections are common. In the field the two species are theoretically easy to distinguish by the characters of the following key, with S. tripartitum being an upright plant, the often decumbent base not rooting, and with erect and branched inflorescences; while S. palitans is a prostrate plant, rooting at the nodes, and with the simple inflorescences holding the fruit at the surface of the soil. The differential characters given in Morton (1976) are not necessarily reliable.
1. Plants decumbent or prostrate, often rooting at the lower nodes, forming a round patch, the branches to 1 m long, the young plants sometimes erect, nearly glabrous to sparsely pubescent in lines with simple hairs to 1 mm long; inflorescence a simple (rarely few-branched) racemose cyme, the peduncle 7–14 mm long, the rachis 4–15 mm long; flowers 4–9 per inflorescence; calyx 2–3 mm long in anthesis, lobed about half way into lanceolate-oblong lobes up to 1.5 x 0.9 mm, accrescent in fruit to 5 x 2.5 mm and covering the basal 1/3 of the berry; berry pale yellow-orange when ripe. Solanum palitans
1.Plants erect and with several branches or spreading to decumbent or even prostrate herbs, generally not rooting even where in contact with the soil, but sometimes rooting at the lowermost nodes, completely glabrous to sparsely pubescent in short lines with simple hairs to 0.4 mm long from the ciliate lower margin of the petiole; inflorescence a 2–9-branched racemose cyme, glabrous or rarely minutely puberulent, the peduncle ca. 10 mm long, the rachises 1–4 cm long, the flowers numerous; calyx 2–2.5 mm long in anthesis, often somewhat swollen at the base, lobed about 1/3 to base into triangular, obtuse lobes ca. 1 x 1 mm, barely accrescent in fruit to 1.5 mm long and not covering the base of the berry; berry passing from green to orange to red when fully ripe.
Solanum tripartitum