Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum diphyllum

Citation author: 
Sp. pl. 184. 1753.
America?, Anon. s.n. (lectotype, LINN 248.5, designated by Knapp & Jarvis, 1991).
Last edited by: 
Knapp, S.
Written by: 
Knapp, S.
Small straggly shrubs 1-2 m tall; stems glabrous or occasionally minutely puberulent with minute white uniseriate trichomes ca. 0.1 mm long, the stems winged from the decurrent leaf bases; bark dark maroon brown, the older stems white lenticellate.
Sympodial structure: 
Sympodial units difoliate, geminate.
Leaves on non-reproductive shoots and lower branches glabrous, oblanceolate, 10-15 x 2.5-4 cm, the apex acute, the base attenuate; petioles 4-5 mm long, winged from the decurrent leaf bases; leaves on the reproductive shoots glabrous, elliptic to oblong, geminate, widest at or just distal to the middle; major leaves 4.7-6.8 x 2-2.2 cm, with 4-5 pairs of main lateral veins raised above, prominent and paler below, the apex rounded or occasionally acute, the base acute to attenuate, decurrent on the stem and petiole; petioles 2-5 mm long; minor leaves ovate to obovate, 0.9-2.5 x 0.6-1.4 cm, the apex rounded, the base acute to attenuate, decurrent on the petiole; petioles 2-3 mm long.
Inflorescences opposite the leaves, simple, glabrous or occasionally minutely glandular, 0.3-1.2 cm long, 5-20-flowered; pedicel scars closely spaced, but not overlapping. Buds globose, white when young, becoming lavendar and more obovoid just before anthesis. Pedicels at anthesis ca. 5 mm long, tapering from the constriction just below the calyx tube to a a slender base ca. 0.5 mm in diam.
Flowers with the calyx tube ca. 1 mm long, with two constrictions, one at the junction with the pedicel and the other just below the lobes, the lobes ca. 1 mm long, deltoid, glabrous; corolla white, often tinged with lavendar, 0.7-1 cm across, lobed 3/4 of the way to the base, the lobes reflexed at anthesis, the interpetalar sinuses thin, extending to the tips of the lobes, the tips of lobes minutely papillose; anthers 1.5-2 x 1 mm, poricidal at the tips, the pores tear-drop shaped; free portion of the filaments ca. 0.5 mm long, the filament tube ca. 0.1 mm long or less; ovary glabrous; style 3-4 mm long, straight, becoming curved with age; stigma minutely capitate, papillose.
Fruit a globose berry, slightly bi-lobed from the two locules, especially when young, 0.7-1.2 cm in diam., green and hard when immature, bright orange and fleshy when ripe; fruiting pedicels erect, woody, ca. 1.2 cm long, with a constriction between the pedicel and calyx tube, ca. 1 mm in diam. at the base.
Seeds pale yellow-tan, flattened-reniform, ca. 3 x 2.5 mm, the surfaces minutely pitted, the margins incrassate, paler than the body of the seed.

Mexico to Pacific Costa Rica in drier lowland areas from 0 to 250 m. Escaped from cultivation in many tropical and subtropical areas: e.g; Florida, Java, and the Antilles.


Solanum diphyllum is a member of the Solanum pseudocapsicum group of the Geminata clade (Knapp, 2002; Bohs, 2005).


Solanum diphyllum is most similar to S. malacothrix, a rare species from western Mexico. The two species share small flowers with reflexed petals at anthesis and berries borne on erect pedicels. Solanum diphyllum differs from S. malacothrix in its glabrous foliage. The mature fruit of S. malacothrix is not known (see discussion under that species).

Solanum diphyllum is native to Mexico and Central America, where it is widespread in drier habitats. It has been widely cultivated as a foliage shrub, and for its pretty flowers and brightly colored fruits, in tropical and subtropical areas where it is hardy such as Italy, southern France, and Florida (D'Arcy, 1974), the Antilles, Java, and the Philippines, and has escaped in some of these areas.

Solanum diphyllum is an attractive shrub, with its tiny white-purple flowers and bright orange fruits. It is self-compatible, but not autogamous. All the flowers are long-styled and the plants set abundant fruit when exposed to pollinators. In cultivation the plants are bushy, with many leaves. In their native Mexico however, shrubs of S. diphyllum are often quite straggly (Nee, pers. comm.).

In Mexico and Central America Solanum diphyllum is remarkably uniform morphologically and is usually easily recognizable. A single geographical variant occurs in Pacific coastal Chiapas. In the municipalities of Arriaga and Cintalapa, near the Mar Muerto on the Pacific coast and somewhat inland, plants of a narrow-leaved race of S. diphyllum are common. Plants from this area have leaves that average 1 cm wide, but otherwise they conform to the other characters of S. diphyllum. Naming this minor variant would obscure its relationship to the rest of the species range.

The type specimen of Solanum diphyllum in LINN is annotated on the back "Solanum lignosum affic. sempervirens, cassinaefoliis. Br." in Linnaeus's handwriting (Savage, 1945). This is perhaps what led D'Arcy (1974) to speculate that the sheet was collected by Patrick Browne, as Linnaeus denoted specimens he received from Browne with a Br. On these sheets however, the specific names were written by Solander (Jackson, 1912). The type comes from the Clifford herbarium (Knapp & Jarvis, 1991; Savage, 1945). The printed vase at the base of the specimen is a characteristic mark of the sheets from that herbarium. Solanum diphyllum was included in the Hortus Cliffortianus (Linnaeus, 1737) as "5. Solanum caule inerme perenni, foliis ovato-lanceolatis geminis, altero minimo." The provenance of the plant was cited as either America or Africa, but Linnaeus emphasized America, so it is clear he thought (correctly) that the plant was from America. Solanum diphyllum was probably cultivated in Clifford's garden, the seeds are easy to grow and even in Ithaca, New York (Bailey Hortorium garden) and London grow to reproductive maturity in one summer.


Linnaeus, C. 1737. Hortus Cliffortianus.
(1968) Reprint, J. Cramer, Lehre, Stuttgart.

Jackson, B.D. 1912. Index to the Linnaean herbarium (with indication of the type species marked by Carl von Linné).
Proc. Linn. Soc. London, suppl. 1911 1912: 1 152.

Savage, S. 1945. A catalogue of the Linnaean Herbarium.
Linn. Soc. London, Taylor & Francis, Ltd., London.

D’Arcy, W.G. 1969. Chromosome Numbers of Phanerogams. 3
Ann. Missouri Bot. Garden. 56(3): 471-475.

D’Arcy, W.G. 1974. Solanum and its close relatives in Florida.
Ann. Missouri Bot. Gard. 61: 819-867.

Knapp, S. & C.E. Jarvis 1990. The typification of the names of New World Solanum species described by Linnaeus.
J. Linn. Soc., Bot. 104: 325-367.

Knapp, S. 2002. Solanum section Geminata (G. Don) Walpers (Solanaceae).
Flora Neotropica 84: 1-405.

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.

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