Citation:
Anales Univ. Santiago 124: 742. 1909.
Type:
Based n Lycopersicon chilense Dunal.
Written by:
Peralta, I.E., S. Knapp & D.M. Spooner
Habit:
Robust perennial herbs, erect becoming decumbent, woody at the base, to 1 m tall, to 1 m in diameter , occasionally spreading in rocky habitats. Stems 8-12 mm in diameter at base, grayish, densely velvety pubescent with simple uniseriate eglandular white trichomes to 0.5 mm long from a unicellular base and bent at the tip, much more abundant on young stems, andscattered short, uniseriate glandular trichomes with 4-celled heads and 8 celled heads amongst the eglandular trichomes.
Sympodial structure:
Sympodial units 2 (rarely 3)-foliate; internodes 1-2 (5) cm long.
Leaves:
Leaves interrupted imparipinnate, (5-) 7-13 (-20) cm long, (2-) 2.5-6.5 (-10) cm wide, grayish green, densely white velvety pubescent with simple uniseriate trichomes like those of the stems, the glandular trichomes fewer, abaxially more densely pubescent and the leaves paler beneath; primary leaflets 5-7 pairs, not markedly decreasing in size towards the base, narrowly elliptic, the base decurrent on the rachis, oblique and the lamina broader basiscopically, the leaflets essentially sessile, the margins irregularly crenate to deeply and irregularly lobed nearly to the leaflet rachis, especially basally, the apex broadly acute to acuminate; terminal leaflet narrower and larger than the laterals, 2-4 cm long, 0.7-2.5 cm wide, the petiolule absent, the base decurrent along the rachis; lateral leaflets 1.2-3.5 cm long, 0.5-1.3 cm wide, the petiolule absent or to 0.1 cm long, in some specimens with especially large leaves; secondary leaflets often present acroscopically on the largest laterals, 0.2-0.4 cm long, 0.05-0.2 cm wide, decurrent on the leaflet rachis; tertiary leaflets absent; interjected leaflets 10-20, often 2 pairs between sets of lateral leaflets, 0.2-0.5 cm long, 0.1-0.3 cm wide, sessile and the base decurrent on the rachis, crowded between the lateral leaflets; petiole 0.5-2 (4) cm long; pseudostipules well developed on most nodes, 0.5-0.9 cm long, 0.4-1.2 cm wide, the margins irregularly crenate.
Inflorescences:
Inflorescences 6-20 (-30) cm, usually once branched and regularly bifurcate, occasionally with additional bifurcations apically and the inflorescence to 3-branched, with (12-) 20-50 flowers, ebracteate or with most nodes bracteate, the bracts 0.5-1.2 cm long, 0.2-0.5 cm wide, the margins irregularly crenate, peduncle 4-15 cm long, densely white velvety pubescent like the stems and leaves. Pedicels 1-1.6 cm long, articulate in the distal half. Buds 0.9-1.2 cm long, 0.3-0.4 cm wide, conical, straight, with the corolla slightly less than halfway exserted from the calyx just before anthesis.
Flowers:
Flowers with the calyx tube 0.05-0.1 cm long, the lobes 0.5-0.6 cm long, 0.1-0.2 cm wide, lanceolate, densely white velvety pubescent on both surfaces; corolla 2-2.6 cm in diameter, rotate-stellate, bright yellow with medial darker midveins on each lobe, the tube 0.4-0.5 (-0.7) cm long, the lobes 1-1.2 cm long, 0.5-0.6 (-0.7)cm wide, sparsely pubescent abaxially with simple, white uniseriate trichomes to 0.25 mm long, these more abundant on the midveins, margins and tips, reflexed at anthesis; staminal column 0.9-1.3 cm long, straight, the filaments less than 0.5 mm long, the anthers 0.5-0.8 cm long, the sterile apical appendage 0.15-0.2 cm long; ovary globose, glabrous or minutely puberulent at the apex; style 1-1.4 cm long, ca. 0.5 mm in diameter, densely white pubescent in the basal half, exserted 0.15-0.2 cm from the staminal column; stigma capitate, green.
Fruits:
. Fruit 1-1.5 cm in diameter, globose, 2-5-locular, greenish white with purple stripes at locule margins when ripe, sparsely to moderately pubescent with weak-walled, simple, white, uniseriate trichomes 0.5-0.7 mm long, these occasionally with unicellular glandular heads, the surface also occasionally with short uniseriate glandular trichomes with 4-celled heads, the fruit surface minutely papillate; fruiting pedicels 1.4-2.1 cm long, straight or slightly bent at the articulation; calyx lobes in fruit 1.2-1.6 cm long, 0.15-0.2 cm wide, narrowing at the base of the sinus, loosely investing the berry or spreading.
Seeds:
Seeds 2.2-3.2 mm long, 1.2-1.6 mm wide, 0.5-0.7 mm thick, obovate, dark brown, pubescent with hair-like outgrowths of the lateral testa cell walls, these adpressed and giving a silky appearance to the surface or sometimes shaggy, narrowly winged (ca. 0.2 mm) at the apex and acute at the base.
Distribution:
On the western slope of the Andes from the Department of Tacna in southern Peru to northern Chile, in hyper-arid rocky plains and coastal deserts from sea level to 3000 m.
Phenology:
Solanum chilense flowers and fruits throughout the year, but there is a distinct a flowering peak in September and October.
Phylogeny:
Solanum chilense is a member of the Potato clade (sensu Weese & Bohs, 2007); within the tomatoes and wild relatives it is a member of the “Eriopersicon group” and is a member of section Lycopersicon.
References:
Philippi, R.A. 1860. Florula Atacamensis, sen Enumeratio Plantarum, quas in itinere per Desertum Atacamense Observavit R. Philippi.
Halis Saxonum: E. Anton.
Rick, C.M., & R. Lamm 1955. Biosystematic studies on the status of Lycopersicon chilense.
Amer. J. Bot. 42: 663–675.
Taxonomic name:
Solanum chilense is remarkably uniform morphologically and relatively easy to distinguish from its close relatives (S. huaylasense, S. peruvianum, S. corneliomulleri) by its stems and leaves that are densely grayish pubescent, straight anther tubes, and long, erect peduncles. It is, however, extremely similar to S. huaylasense from Ancash in northern Peru, with which it shares the elongate peduncle and branched inflorescence. The densely canescent pubescence of S. chilense, giving the plant a grayish cast, serves to distinguish the two taxa easily, and in general, the flowers of S. chilense are larger than those of S. huaylasense.
Rick & Lamm (1955) undertook a broad series of crossing studies in order to test whether or not S. chilense deserved specific status. They concluded that S. chilense should be recognized as a distinct species because it could not cross easily with other species, had a distinctive morphology, and occurred at the southern range of wild tomatoes.
B. Igic (pers. comm.) has discovered populations of S. chilense in the region of Taltal in northern Chile that are markedly different in some key genetic factors. Herbarium specimens, however, do not show substantial morphological differences from other populations throughout the range of the species and appear to be identical to S. chilense in all major respects. These populations merit further study.
Although Philippi (1860) cited two localities (Paposo and Tilopozo) in his original description of Lycopersicon atacamense. The only extant candidate for the type specimen at SGO bears a label in Philippi’s hand with both localities on the single specimen. In his description of Lycopersicon puberulum, Philippi states only “in Peruvia australiore”, but the sheet in SGO has more complete information, cited above.