Citation:
Revis. Argent. Solanum, p. 92. 1976.
Type:
Argentina. Tucumán: Depto. Capital [“Tafí del Valle” on isotype at SI], Yerba Buena, 470 m, 19 Jan 1919, S. Venturi 159 (holotype, US [US-1548805, photo, US].; isotypes: BA, LIL, SI, LP).
Last edited by:
Nee, M., S. Croutch, K. Watson & L. Bohs
Habit:
Decumbent or prostrate herbs, often rooting at the lower nodes, forming a round patch, the branches to ca. 1 m long, the young plants sometimes erect. Stems nearly glabrous to sparsely pubescent in lines with simple hairs to 1 mm long.
Sympodial structure:
Sympodial units 2-foliate, not geminate.
Leaves:
Leaves simple, the blades 2.5–9 x 2.5–7.5 cm, ca. 1-1.4 times as long as wide, broadly ovate, chartaceous, glabrous to sparsely pubescent adaxially with simple hairs to 0.5 mm on the major veins, glabrous abaxially; base long attenuate; margin 3-lobed nearly to the midrib, rarely the lateral lobes bi-lobed, the terminal lobe ovate, the lateral lobes asymmetrically ovate or lance-ovate, acute at the tips, the interlobal sinuses sometimes sparsely ciliate; apex acute; petioles 0.5-2 cm, 1/6 to 1/3 as long as the blade, winged to the base, glabrous or sometimes sparsely ciliate near the base.
Inflorescences:
Inflorescences 1.2-2.5 cm, extra-axillary, often just below a node, unbranched or rarely few-branched, with 4-9 flowers, all flowers apparently perfect, the axes glabrous to sparsely pubescent; peduncle 0.7-1.4 cm; rachis 0.4-1.5 cm; pedicels 3-5 mm in flower, 6-8 mm in fruit, recurved at the base to hold the fruit downwards, nearly in contact with the soil, the apex often angulate or slightly winged from the base of the calyx, spaced 1-5 mm apart, articulated at the base.
Flowers:
Flowers all hermaphroditic, 5-merous. Calyx 2–3 mm long, the tube 1.5-2 mm, the lobes ca. 0.75-1.5 x 0.6-0.9 mm at the base, lanceolate-oblong, glabrous; fruiting calyx accrescent to ca. 5 x 2.5 mm and covering the basal 1/3 of the berry, the lobe tips somewhat recurved. Corolla ca. 0.7 cm in diameter, 3.75-5 (-6.25) mm long, rotate-stellate, chartaceous, white or rarely light violet, the tube 2-3 (-4.25) mm long, the lobes 1.5-2.5 x 1-2 mm at the base, triangular, abaxially minutely white-puberulent on the tips of the lobes, glabrous adaxially. Stamens with filaments ca. 1 mm, pubescent; anthers 1.6 x 0.7–0.8 mm, oblong, somewhat connivent, yellow, dehiscent by broad pores at the tip and partially longitudinally. Ovary glabrous; style 2.25-3.25 x ca. 0.2 mm, cylindrical, glabrous or sparsely pubescent; stigma capitate.
Fruits:
Fruits 6–8 mm in diameter, slightly bilobed, especially when young, depressed-globose when ripe, pale yellow-orange, glabrous, the mesocarp juicy.
Seeds:
Seeds numerous, 1.6 x 1.2 mm, flattened-reniform, light yellow.
Phenology:
Mostly flowering and fruiting in the rainy season, from December through May, but occasionally found at other times of the year, in situations where water is available in weedy habitats near villages. Breeding system.
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