Solanum quitoense [Lam. ]

Solanum quitoense

Citation author:

Lam.

Citation:

Illustr., 2: 16, no. 2326. 1793 [1794].

Type:

Cultivated at Paris, “ex Amer. Merid.” (Holotype: P-LAM; isotype: P-JUSS [photos of both specimens at US, WIS]).

Last edited by:

Bohs, L.

Written by:

M.D. Whalen, D.E. Costich and C.B. Heiser, Jr.

Habit:

Erect or divergently branched, lignescent perennials 1-3 m tall. Stems stellate-woolly, densely pubescent with a mixture of stipitate to essentially sessile stellate trichomes, the multiseriate stalks of stipitate cauline stellae of variable length, the longest 1-4 mm, the lateral rays 6-9, 0.6-1.5 mm long, the midpoints about equaling rays or somewhat shorter, the hairs often purplish; unarmed or prickly, the prickles, when present, small, 1-3 (-5) mm long, 0.5-1.5 mm broad at base, usually somewhat recurved.

Sympodial structure:

Sympodial units 2-foliate, geminate.

Leaves:

Leaves simple, the blades 13-50 x 11-40 cm, about as long as wide, elliptic to ovate, thin-textured, felty-pubescent adaxially with sessile stellae, the dominant form with prolonged midpoints 1-2 mm long and 4-6 short, basally inserted lateral rays 0.1-0.4 mm long, also with a distinct class of smaller stellae often scattered among the larger ones, with rays and midpoints 0.1-0.3 mm long, densely pubescent abaxially with interwoven stalked and sessile stellae, the foliar pubescence in vivo with purplish cast, especially along principal veins; unarmed or sparsely prickly on major veins; major lateral veins 5-6 on each side; base truncate or shallowly cordate; margin coarsely dentate with 5-6 deltoid or depressed-deltoid, acute- or obtuse-tipped lobes at lateral vein terminations, the interlobal sinuses entire or occasionally with 1 or 2 smaller, tooth-like lobes; apex acute; petioles 5-15 cm, typically 1/4-1/2 the length of the blades, densely pubescent with hairs like those of the stem, unarmed or sparsely prickly.

Inflorescences:

Inflorescences up to 1 cm long, leaf-opposed, unbranched, with 1-24 flowers, the distal flowers mostly female-sterile, the axes densely stellate-pubescent, unarmed or minutely prickly; peduncle 0-0.5 cm; rachis ca. 0.5 cm; pedicels 5-15 mm in flower, 5-15 mm in fruit, closely spaced 2-3 mm apart, articulated at the base.

Flowers:

Flowers with the calyx broadly campanulate, 14-20 mm long, the tube 5-8 mm, 8-13 mm wide, the lobes 7-13 x 5-8 mm, ovate to broadly ovate, commonly somewhat petaloid and white, stellate-woolly abaxially; fruiting calyx somewhat accrescent but not completely covering the fruit. Corolla 3-5 (-7) cm in diameter, 20-25 mm long, stellate, the tube 4-6 mm, thin-textured, white, the lobes 10-15 x 5-7 mm, ovate-lanceolate, spreading, acute at apices, densely stellate-pubescent abaxially, glabrous or sparsely pubescent adaxially. Stamens with filaments 0-1 mm; anthers 7-15 x 2-3.5 mm at base, lanceolate, attenuate, more or less connivent or divergent at tips, yellow, the pores small and directed distally. Ovary densely pubescent; style ca. 10 x 0.5-1mm, cylindrical, straight, glabrous; stigma capitate.

Fruits:

Fruits 1-4 per inflorescence, 3-6.5 cm in diameter, globose, orange when ripe, with green flesh, spreading-hirsute when young with sessile stellate hairs with with elongate midpoints 3.5-4.5 mm long and 5-15 short, basally inserted lateral rays ca. 0.2 mm long, most trichomes finally deciduous.

Seeds:

Seeds numerous, 2.5-4 x 2.5-4 mm, yellow or light tan, lenticular, broadly ovate, the surfaces minutely pitted.

Chromosome number:

2n = ploidy missing =24 voucher missing =

Distribution:

Cultivated between 1000 and 2400 m in mountains of Colombia and Ecuador; recently introduced and becoming a successful weed in montane regions of Costa Rica and Panama.

Phylogeny:

Solanum quitoense belongs to the Leptostemonum clade of Solanum (Bohs, 2005). Within Leptostemonum, it belongs to the Lasiocarpa clade, a monophyletic group that includes most of the species traditionally recognized in Solanum section Lasiocarpa Dunal (Whalen et al., 1981; the S. quitoense species group of Whalen, 1984; Levin et al., 2006). Within this clade, chloroplast sequences from the trnT-F region indicate that S. quitoense belongs to a clade that also includes S. candidum, S. hyporhodium, S. lasiocarpum, S. felinum, S. pseudolulo, S. repandum, and S. vestissimum (Bohs, 2004). Resolution is poor to non-existent among the species of this latter clade.

Commentary:

Commentary taken from Whalen et al. (1981):

Solanum quitoense is cultivated for its edible fruit in highlands of Colombia and Ecuador. It is used predominantly for juice and in preparation of refrescos with sugar and ice. The lulo is one of the most delightful of tropical American fruits, with a flavor reminiscent of citrus, and is rich in Vitamin A and ascorbic acid (Romero-Castañeda, 1961). Cultivation of S. quitoense is restricted by climatic requirements and susceptibility to root-knot nematode infection (Munier, 1962). It is most commonly grown in small plantings on newly cleared land.

Wild occurrences of S. quitoense in Colombia and Ecuador are generally attributed to escape from cultivation. Volunteer plants are seen in disturbances and around habitations in regions where the species is cultivated. For reasons we do not understand, S. quitoense has been most successful as a weed in Costa Rica and Panama, where it was introduced into cultivation in this century. A few collections from montane forests in Colombia may represent native populations (Cuatrecasas et al. 12111 from Norte de Santander and Cuatrecasas 15031 and 22694 from the Cordillera Occidental in Valle). The regions in which these plants were found should be explored more fully as potentially important sources of germ plasm.

Heiser (1969) speculates that S. quitoense was domesticated in highlands of central Colombia and transported by man to Ecuador and Peru. The basis for the argument is the existence of prickly forms and close relatives in the former region. The opposite direction of introduction, into Colombia from Ecuador, is postulated by Patiño (1962) and Schultes and Romero-Casteñeda (1962). Morphological data from Colombian and Ecuadorean plants point to a relative lack of variability in Ecuadorean S. quitoense. The pattern observed may be due to founder effect associated with human dispersal of S. quitoense southward in the Andes from a region of initial domestication in central Colombia as proposed by Heiser.

Heiser (1972) pointed out the close relationship of S. quitoense to S. candidum, a wide ranging species extending from Mexico to Peru. The morphological similarity between these taxa is great, and the differences between them are primarily in characters that would likely have been influenced by human selection during the process of domestication. In particular, S. quitoense is unarmed or only sparsely prickly and has larger fruits with more readily deciduous hairs than S. candidum. An additional difference is the green flesh of S. quitoense fruits, an attribute of that species not found in any other members of section Lasiocarpa.

References:

Romero-Castañeda, R. 1961. El lulo: una fruta de importancia economica.
Agricultura Tropical 17: 214-218.

Schultes, R.E., & R. Romero-Castañeda 1962. Edible fruits of Solanum in Colombia.
Botanical Museum Leaflets 19: 235-286.

Patiño, V.M. 1962. Edible fruits of Solanum in South American historic and geographic references.
Botanical Museum Leaflets 19: 215-234.

Munier, R. 1962. La Culture du lulo en Colombia.
Fruits 17: 91-92.

Heiser, C.B., Jr. 1969. Nightshades, the paradoxical plants.
Freeman, San Francisco.

Whalen, M.D., D.E. Costich & C.B. Heiser, Jr. 1981. Taxonomy of Solanum section Lasiocarpa.
Gentes Herb. 12: 41-129.

Whalen, M.D. 1984. Conspectus of species groups in Solanum subgenus Leptostemonum.
Gentes Herbarum 12 (4): 179-282.

Heiser, C.B., Jr. 1985. Ethnobotany of the naranjilla (Solanum quitoense) and its relatives.
Econ. Bot. 39: 4-11.

Bohs, L. 2004. A chloroplast DNA phylogeny of Solanum section Lasiocarpa (Solanaceae).
Syst. Bot. 29: 177-187.

Heiser, C., J. Soria, C. Miller, & G. Anderson 2005. A new synthetic allopolyploid naranjilla, Solanum indianense (Solanaceae).
Novon 15: 290-292.

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.

Levin, R.A., N.R. Myers, & L. Bohs 2006. Phylogenetic relationships among the "spiny" solanums (Solanum subgenus Leptostemonum).
Amer. J. Bot. 93: 157-169.

Genetics:

nuclear ITS sequence: GenBank AY263460 (Jardín Botanico de Bogotá, Colombia, Olmstead, no voucher) nuclear waxy (GBSSI) sequence: GenBank AY562965 (voucher: Bohs 2873, UT) chloroplast trnS-G sequence: GenBank AY555471 (voucher: Bohs 2873, UT) chloroplast trnT-F sequence: GenBank AY266243 (voucher: Heiser s.n.; Bohs DNA extract 996; plant from Quito, Ecuador, market) http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=33355744 chloroplast trnT-F sequence: GenBank AY266228 (voucher: Bohs 2873, UT) http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=33355729

Solanaceae Source

A global taxonomic resource for the nightshade family

Solanaceae

Solanum quitoense Lam.

Primary tabs

NCBI