Gesneriaceae
Read about Gesneriaceae in the Standard Cyclopedia of Horticulture
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Gesneriaceae (from the genus Gesneria, named after the early botanist Conrad Gesner of Zurich). Gesneria Family. Fig. 53. Herbs, rarely shrubs or small trees, sometimes climbing: leaves usually opposite or whorled, simple: flowers bisexual, irregular, often bilabiate; calyx 5-parted; corolla 5-lobed, gamopetalous, hypogynous, often gibbous below, imbricated; stamens rarely 5, usually 4 and didynamous, rarely 2, the sterile usually present as staminodia, epipetalous; hypogynous disk present, diverse; ovary superior or inferior, of 2 carpels but 1-celled with 2 parietal placentae, often falsely 2-4-celled; ovules numerous; style 1; stigmas 1-2: fruit fleshy with pulpy placentae, or capsular, or silique-like with twisted valves. Eighty-four genera and about 500 species are widely distributed in the tropics and subtropics of both hemispheres. The largest genera are Cyrtandra containing 180 species and Roettlera with about 100 species. The family is related to the Scrophulariaceae, Orobanchaceae and Bignoniaceae. The 1-celled ovary without winged seeds, and the non-parasitic habit are distinctive. The only economic plants in the family are the ornamental, of which there are many. The flowers throughout the family are uncommonly large and showy. Twenty or more genera are in cultivation in N. America. Among these are the following, all of greenhouse culture: Agalmyla, climbers; Episcia; Gesneria; Isoloma (Kohleria); Naegelia (Smithiantha); Saintpaulia (Usambara Violet; African Violet); Sinningia, including the Gloxinias; Streptocarpus (Cape Primrose); Trichosporum (or Aeschynanthus), trailing or drooping.
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Gesneriaceae is a family of flowering plants consisting of ca. 150 genera and ca. 3200 species in the Old World and New World tropics and subtropics, with a very small number extending to temperate areas. Most species are perennial herbs or subshrubs but a few are woody shrubs or small trees. On the basis of both morphological and biogeographical differences the family is divided into two major subfamilies: subfamily Cyrtandroideae in the Old World and subfamily Gesnerioideae in the New World. The biggest and most widespread genus is Cyrtandra, with about 600 species widely distributed in Southeast Asia, Malaysia, Indonesia, the Philippines, and the islands of the Pacific as far away as the Hawaiian Islands.
Several genera in the family have become popular as houseplants. The most familiar members of the family to gardeners are the African Violets in the genus Saintpaulia. Gesneriads are divided culturally into three groups on the basis of whether, and how, their stems are modified into storage organs: rhizomatous, tuberous, and "fibrous-rooted", meaning those that lack such storage structures (although all gesneriads have fibrous roots).
The genus Rehmannia has sometimes been included in Gesneriaceae but is now referred to the family Scrophulariaceae.
Botanists who have made significant contributions to the systematics of the family are George Bentham, Robert Brown, B.L. Burtt, C.B. Clarke, Olive M. Hilliard, Joseph Dalton Hooker, William Jackson Hooker, Elmer Drew Merrill, Harold E. Moore, Jr., Conrad Vernon Morton, Henry Nicholas Ridley, Laurence Skog, W.T. Wang, Anton Weber, and Hans Wiehler. Several researchers are currently working on this group and the generic classification has been changing rapidly.
The family name is based on the genus Gesneria, which honors Swiss humanist Conrad Gessner.
- Selected genera
External links
- World Checklist of Gesneriaceae
- Genera of Gesneriaceae
- Gesneriad Reference Web
- Gesneriaceae: A Scientific Overview, by Prof. Anton Weber (on the Gesneriad Reference Web)
- The Gesneriad Society (formerly the American Gloxinia and Gesneriad Society)
- Annotated Bibliography of the Gesneriaceae
- Phylogenetic relationships in the Gesnerioideae (Gesneriaceae) based on nrDNA ITS and cpDNA trnL-F and trnE-T spacer region sequences (link to abstract)
- Evolution of Cyrtandra (Gesneriaceae) in the Pacific Ocean: the origin of a supertramp clade
- Weber, A. 2004. Gesneriaceae and Scrophulariaceae: Robert Brown and now. Telopea 10(2): 543-571.