Nightshade Family

Janet R. Sullivan

Herbs, annual or perennial, vines, shrubs, or trees, sometimes rhizomatous or tuberous, usually hermaphroditic, sometimes gynodioecious or dioecious in Lycium [andromonoecious or dioecious in some Solanum]. Stems erect or decumbent to prostrate, sympodially branched, glabrous or pubescent, hairs simple, dendritic, or stellate, stalked-vescicular in Quincula, sometimes peltate scales in Solanum, glandular or eglandular, glands sessile or stalked and sometimes multicellular, sometimes prickly or spiny. Leaves alternate and spiral or unequally paired, simple or pinnately compound [trifoliolate], estipulate, petiolate or sessile; blade margins entire, dentate, lobed, or divided. Inflorescences terminal, axillary, extra-axillary, in forks of dichotomous branches in some Datura and Solanum, racemose, paniculate, umbellate, or glomerulate cymes, in fascicles of 2–6, or solitary flowers. Flowers bisexual or rarely unisexual, radially symmetric or, less frequently, bilateral; perianth and androecium hypogynous; sepals (4 or)5, connate for almost full length to only at base, tubular, campanulate, obconic, or cyathiform [urceolate], with 3–10 equal or unequal lobes, lobules, or teeth, 5–10 veins extending into appendages that protrude below a truncate rim in Lycianthes, bases of lobes sagittate to cordate in Nicandra; calyx usually persistent in fruit and often accrescent, circumscissile and leaving a basal remnant that is slightly enlarged in some species of Datura, sometimes spreading, reflexed, or expanded to partially or completely enclose fruit, sometimes becoming membranous, sometimes inflated and bladderlike; petals (4 or)5, connate for almost full length to only at base, stellate, campanulate, campanulate-rotate, rotate, funnelform, salverform, or urceolate [crateriform, cylindric], margins nearly entire or shallowly to deeply 4–10-lobed, lobes sometimes widely flaring or reflexed, corona present between tube and limb in Nectouxia; stamens (2 or 4 plus staminodes or)5, variously adnate to corolla from near base nearly to rim, with appendage at point of fusion in Cestrum, equal or unequal in length, anthers sometimes connivent, basi-, dorsi-, or ventrifixed, with unequal thecae in Bouchetia, Browallia, and Hunzikeria, connective sometimes thickened, with 2 dorsal wings in Nectouxia, dehiscence longitudinal or poricidal; pistil 1, 2–5-carpellate; ovary superior, nectary disc sometimes present at base, [1 or]2–5[or 10]-locular, [1 or]2–many ovules per locule, placentation axile; style 1, stigma rounded-truncate, capitate, or 2–5-lobed. Fruits usually berries or 2–4-valved capsules, dehiscence septicidal, circumscissile, or irregular [septifragal, septicidal-loculicidal], sometimes drupaceous in Lycium [schizocarp of nutlets in Nolana]. Seeds 1–many, whitish to straw-colored to dark brown or black, often flattened and discoidal or reniform, sometimes globose, ovoid, prismatic, or angulate, with hyaline margin in Oryctes, with white caruncle in some species of Datura, intermixed with sclerotic granules in Calliphysalis and some Solanum; embryo straight or curved, endosperm usually abundant.

Genera ca. 97, species ca. 2500 (27 genera, 151 species, including 2 hybrids, in the flora): nearly worldwide.

Solanaceae occur on all continents except Antarctica, but their greatest diversity is in the Neotropics. Their closest relative is the Convolvulaceae, from which they can be distinguished by growth form (when herbaceous vines, not with twining stems), the usually 2-locular ovary with numerous ovules, and the absence of laticifers with milky sap. Members of the Solanaceae exhibit a sympodial growth pattern, resulting in unusual placement of leaves, branches, and flowers (A. Child 1979). The foliage of some Solanaceae is fetid or pungent (reminiscent of rotting potatoes or with a sharp, tomato-like smell). The vegetative portions of most members of the family are poisonous due to the presence of tropane and steroidal alkaloids.

Despite the toxicity of its foliage, many Solanaceae species are of worldwide economic importance, such as tomato (Solanum lycopersicum), eggplant (S. melongena), potato (S. tuberosum), chili and bell peppers (Capsicum spp.), tobacco (Nicotiana tabacum), and Petunia. The family also includes many species of small-scale crop, medicinal, or horticultural importance. The most well known of these in the flora area are tomatillo (Physalis philadelphica), belladonna (Atropa belladonna), goji berry (Lycium barbarum and L. chinense), Chinese lantern plant (Alkekengi officinarum), jimsonweed (Datura spp.), jessamine (Cestrum spp.), and Calibrachoa.

The fruit in the Solanaceae is typically a berry or capsule (with circumscissile dehiscence in Hyoscyamus), but may be hardened and drupaceous in some Lycium. The berry-fruited taxa may have a thick, juicy pericarp, or one that is dry and thin, ultimately shattering into irregular pieces. Many genera have an accrescent calyx. The most enlarged of these may become rigid and spinescent (Hyoscyamus), inflated and almost closed around the berry (Alkekengi, Calliphysalis, Physalis, Quincula), loose and enveloping all (Nicandra) or at least the basal half of the berry (Chamaesaracha), or reflexed or flaring (Jaltomata). The brightly colored, juicy berries of many species are animal dispersed. The inflated, bladderlike calyces in several genera also aid in dispersal (short distance by water or ground level by wind).

The showy flowers of Solanaceae are pollinated by bees, flies, butterflies, moths, or humming­birds foraging for nectar and/or pollen. Solanum does not produce nectar, and pollen is gath­ered by vibration (buzz pollination) or manipulation of the anthers. Flowers of Cestrum, Datura, and some Nicotiana emit a strong, sweet fragrance in the evening and are moth-pollinated.

Some Solanaceae grown as ornamentals have escaped and persisted for short periods but have not become established in the flora. Nierembergia hippomanica Miers var. coerulea R. Millan has been collected from disturbed sites in Texas (1958, 1962, 1998), and N. scoparia Sendtner was found along a roadside in Georgia in 1947. Nierembergia Ruiz & Pavon is a South American genus. Brugmansia suaveolens (Humboldt & Bonpland ex Willdenow) Sweet, also native to South America, was found in a ruderal yard (2001) and wooded ravine (1983) in Florida. Brugmansia has been treated as part of Datura, but it can be distinguished from that genus by its woody habit, pendulous flowers, and elongated, spineless fruits.

Since the early 1990s, our understanding of the circumscription of the Solanaceae, as well as phylogenetic relationships within the family, have been clarified using both morphological and molecular characters, particularly chloroplast DNA sequence data (W. G. D’Arcy 1991; A. T. Hunziker 2001; T. R. Martins and T. J. Barkman 2005; R. G. Olmstead and L. Bohs 2007; Olmstead and J. D. Palmer 1991, 1992; Olmstead et al. 1999, 2008; T. Särkinen et al. 2013). Based on molecular data, the family is considered monophyletic with the inclusion of Nolana Linnaeus f., Schizanthus, and Sclerophylax Miers. The subfamilies Solanoideae Burnett and Cestroideae Burnett, traditionally recognized on the basis of morphology alone, have been shown to be nonmonophyletic. Some generic concepts have been revised; changes relevant to the flora area are discussed under the various genera.

SELECTED REFERENCES Child, A. 1979. A review of branching patterns in the Solanaceae. In: J. G. Hawkes et al., eds. 1979. The Biology and Taxonomy of the Solanaceae. London. Pp. 345–356. D’Arcy, W. G. 1991. The Solanaceae since 1976, with a review of its biogeography. In: J. G. Hawkes et al., eds. 1991. Solanaceae III: Taxonomy, Chemistry, Evolution. Kew. Pp. 75–137. D’Arcy, W. G., ed. 1986. Solanaceae: Biology and Systematics. New York. Hawkes, J. G. et al., eds. 1979. The Biology and Taxonomy of the Solanaceae. London. Hawkes, J. G. et al, eds. 1991. Solanaceae III: Taxonomy, Chemistry, Evolution. Kew. Hunziker, A. T. 2001. Genera Solanacearum: The Genera of Solanaceae illustrated.... Ruggell. Keating, R. C., V. C. Hollowell, and T. B. Croat. 2005. A Festschrift for William G. D’Arcy: The Legacy of a Taxonomist. St. Louis. Knapp, S. 2002. Floral diversity and evolution in the Solanaceae. In: Q. C. B. Cronk et al., eds. 2002. Developmental Genetics and Plant Evolution. London. Pp. 267-297. Martins, T. R. and T. J. Barkman. 2005. Reconstruction of Solanaceae phylogeny using the nuclear gene SAMT. Syst. Bot. 30: 435–447. Nee, M. et al. 1999. Solanaceae IV: Advances in Biology and Utilization. Kew. Olmstead, R. G. et al. 1999. Phylogeny and provisional classification of the Solanaceae based on chloroplast DNA. In: M. Nee et al., eds. Solanaceae IV: Advances in Biology and Utilization. Kew. Pp. 111–137. Olmstead, R. G. et al. 2008. A molecular phylogeny of the Solanaceae. Taxon 57: 1159–1181. Olmstead, R. G. and L. Bohs. 2007. A summary of molecular systematic research in Solanaceae: 1982–2006. In: D. M. Spooner et al. eds. 2007. Solanaceae VI: Genomics Meets Biodiversity.... Leuven. [Acta Hort. 745.] Pp. 255–268. Olmstead, R. G. and J. D. Palmer. 1991. Chloroplast DNA and systematics of the Solanaceae. In: J. G. Hawkes et al., eds. 1991. Solanaceae III: Taxonomy, Chemistry, Evolution. Kew. Pp. 161–168. Olmstead, R. G. and J. D. Palmer. 1992. A chloroplast DNA phylogeny of the Solanaceae: Subfamilial relationships and character evolution. Ann. Missouri Bot. Gard. 79: 346–360. Rydberg, P. A. 1896b. The North American species of Physalis and related genera. Mem. Torrey Bot. Club 4: 297–372. Spooner, D. M. et al., eds. 2007. Solanaceae VI: Genomics Meets Biodiversity.... Leuven. [Acta Hort. 745.] Van den Berg, R. G. et al. 2001. Solanaceae V: Advances in Taxonomy and Utilization. Nijmegen.