Gesneriaceae Rich. & Juss.

Gesneriaceae, O. M. Hilliard and B. L. Burtt. Flora Zambesiaca 8:3. 1988

Morphology General Habit

Acaulescent or caulescent herbs, or rarely shrubs

Morphology Leaves

Leaves opposite (rarely alternate), those of a pair equal or unequal; plants sometimes unifoliate and the leaf cotyledonary in origin

Morphology Reproductive morphology Inflorescences

Inflorescence generally of open axillary cymes, the flowers at each dichotomy being paired and opening serially; occasionally much congested and sub-capitate, or pseudoracemose

Morphology Reproductive morphology Flowers

Flowers hermaphrodite (very rarely unisexual) often large and showy, sometimes cleistogamous with reduced corolla

Morphology Reproductive morphology Flowers Calyx

Calyx tubular and 5-lobed or divided to the base or 3 upper lobes only united

Morphology Reproductive morphology Flowers Corolla

Corolla gamopetalous with distinct tube, often bilabiate, proportion of lobes to tube variable; lobes imbricate, and adaxial pair often inside

Morphology Reproductive morphology Flowers Androecium

Stamens usually 4 or 2, rarely 5, inserted on corolla tube; anthers free or variously connate, 2-celled, opening longitudinally

Morphology Reproductive morphology Flowers Nectaries

Disk annular or cup-like, often lobed or undulate, rarely oblique or absent

Morphology Reproductive morphology Flowers Gynoecium

Ovules numerous Ovary superior, unicellular with 2 parietal bilamellate placentas, occasionally bilocular by their union centrally

Morphology Reproductive morphology Fruits

Fruit a capsule (often linear, sometimes spirally twisted) or a more or less fleshy berry

Morphology Reproductive morphology Seeds

Seeds numerous, small, more or less ellipsoid, sometimes tailed with hair-like appendages at either end; endosperm absent or very slight

Chautems, A. (2009). Neotropical Gesneriaceae.

Morphology

Description

Adapted from Weber (2004), with pollen data from E. Gasparino (unpublished thesis, 2008).

Perennial herbs with basalscaly rhizomes, tubers or fibrousroots, subshrubs, small trees, vines, climbers or epiphytes. Leavessimple, opposite or in whorls, rarely alternate; green, sometimes reddish or with wine-red blotch on abaxial face, stomata scattered or in groups. Inflorescences of pair-flowered axillary cymes , pedunculate or epedunculate, bracteolate or ebracteolate, one to many-flowered. Flowers gamopetalous, zygomorphic, rarely actinomorphic, of various shapes, white or brightly colored. Stamens 4, rarely 5, staminode usually present, anthers cohering in pairs or all together, sometimes free. Nectary annular or consisting of 2 to 5 separate glands, free from the ovary wall, rarely reduced and non-functional, or completely lacking, sometimes replaced by an osmophore near the base of the corolla. Ovarysuperior, semi- or completely inferior, usually ovoid or globose, unilocular, placentae parietal, T-shaped in cross-section. Fruit a dry or fleshy 2-(rarely 4- ) valved capsule with placentae exposed as a central cone or split in two (display capsule), or an indehiscent white or colored berry. Seeds usually without surface ornamentation of testa cells, often striate. Seedlings isocotylous.

General Description

Notes on delimitation

• The family forms a monophyletic group within Lamiales.
• The subfamily Gesneroideae is exclusively neotropical.
• 7 tribes are recognized, i. e. Beslerieae (BESL), Episcieae (EPIS), Gesnerieae (GESN), Gloxinieae. (GLOX), Napeantheae (NAPE), Sinningieae (SINN) and Sphaerorrhizae (SPHAE).

Status

• Some genera are cultivated as ornamentals (mostly indoor plants), and among the most popular are Achimenes, Codonanthe, Columnea, Gloxinia, Episcia, Kohleria, Nematanthus, Sinningia, Seemannia.
• Plants are easy to propagate by cuttings or by seeds
• They also hybridize easily within related groups and many cultivars are available.

General notes

Distribution and ecology: rain forest on mountain slopes with main diversity center between Colombia and Peru (over 400 spp.) and secondary centers in Central America (ca. 250 spp.), eastern Brazil (over 200 spp.), Guiana shield (ca. 100 spp.) and tropical Mexico (ca. 100 spp.).

Number of genera

• ca. 60 genera.

Distribution

Distribution in the Neotropics

Some 1200 species, ca. 60 genera in seven tribes:

• Achimenes Pers., GLOX/ 27: Mexico, C. America, Caribbean, N. South America.
• Alloplectus Mart., EPIS/ 6: NW South America, Costa Rica.
• Alsobia Hanst., EPIS/ 2: Mexico, Costa Rica.
• Amalophyllon Brandegee, GLOX/ 5: Mexico, NW South America.
• Anetanthus Hiern ex Benth., BESL/ 2: Colombia to Bolivia, C Brazil .
• Bellonia L., GESN/ 2: Cuba, Hispaniola.
• Besleria L., BESL/ 150: Widespread.
• Chrysothemis Decne., EPIS/ 6: Caribbean, Guatemala to Ecuador, Guianas, N Brazil.
• Cobananthus Wiehler,  EPIS/ 1: Guatemala & Honduras.
• Codonanthe (Mart.) Hanst., EPIS/ 19: Widespread.
• Codonanthopsis Mansf., EPIS/ 4: NW South America, N Brazil, Guianas.
• Columnea L., EPIS/ 200: Mexico to Bolivia, Guianas, Caribbean, E Brazil.
• Corytoplectus Oerst., EPIS/11: NW South America to Bolivia, Guyana, N Brazil.
• Crantzia Scop., EPIS/ 4: Venezuela, Guyana, Caribbean.
• Cremersia Feuillet & L. E. Skog,  EPIS/ 1: French Guiana.
• Cremosperma Benth., BESL/ 21: Costa Rica to Peru.
• Cremospermopsis L. E. Skog & L. P. Kvist,  NAPE/ 2: Colombia.
• Diastema Benth., GLOX/ 21: Mexico, NW South America.
• Drymonia Mart., EPIS/ 70: Widespread.
• Episcia Mart., EPIS/ 8: Mexico to Peru, N Brazil, Guianas.
• Eucodonia Hanst., GLOX/ 2: Mexico.
• Gasteranthus Benth., BESL/ 38: Mexico to Bolivia.
• Gesneria L., GESN/ 55: Caribbean.
• Glossoloma Hanst., EPIS/ 22: Mexico to Bolivia.
• Gloxinella Roalson & Boggan,  GLOX/ 1: Peru.
• Gloxinia L'Her., GLOX/ 3: C & S America, Caribbean.
• Gloxiniopsis Roalson, GLOX & Boggan/ 1: Colombia.
• Goyazia Taub., GLOX/ 2: C Brazil.
• Heppiella Regel, GLOX/ 4: NW S America, Venezuela.
• Kohleria Regel, GLOX/ 20: Mexico, NW South America, Caribbean.
• Lampadaria Feuiilet & L. E. Skog,  EPIS/ 1: Guyana.
• Lembocarpus Leeuwenb.,  EPIS/ 1: French Guiana, Surinam.
• Mandirola Decne., GLOX/ 3 : C Brazil.
• Monopyle Moritz ex Benth.,  GLOX/ 18: Guatemala to NW South America.
• Moussonia Regel, GLOX/ 12: Mexico to Panama.
• Napeanthus Gardner, NAPE/ 18: Mexico to South America.
• Nautilocalyx Linden ex Hanst.,  EPIS/ 51: Widespread.
• Nematanthus Schrad., EPIS/ 30: E Brazil.
• Neomortonia Wiehler, EPIS/ 2: Mexico, C. America to Ecuador.
• Niphaea Lindl., GLOX/ 4: Mexico, C America.
• Oerstedina Wiehler, EPIS/ 3: Mexico, C America.
• Paliavana Vand., SINN/ 6: E Brazil.
• Paradrymonia Hanst., EPIS/ 38: Mexico to Bolivia, Guianas, N Brazil.
• Pearcea Regel, GLOX/ 17: Colombia to Bolivia.
• Pheidonocarpa L.E.Skog, GESN/ 1: Cuba, Jamaica.
• Phinaea Benth., GLOX/ 3: Mexico, NW South America, Caribbean, N Brazil.
• Reldia Wiehler, BESL/ 5: Costa Rica to Peru.
• Resia H.E.Moore, NAPE / 2: Colombia, Venezuela.
• Rhoogeton Leeuwenb.,  EPIS/ 2: Venezuela, Guyana.
• Rhynchoglossum Blume, Epithematoid/ 1: Mexico to Honduras, Costa Rica to Peru (only genus belonging to the paleotropical Epithematoid group with one species ocurring in the Neotropics).
• Rhytidophyllum Mart., GESN/ 18: Caribbean.
• Rufodorsia Wiehler, EPIS/ 4: Nicaragua to Panama.
• Seemannia Regel, GLOX/ 4: Ecuador to N Argentina, Brazil.
• Sinningia Nees, SINN/ 72: Mexico to S America.
• Smithiantha Kuntze, GLOX/ 6: Mexico.
• Solenophora Benth., GLOX/ 16: Mexico to Panama.
• Sphaeorrhiza Roalson & Boggan,  SPHAE/ 3: C. Brazil.
• Tylopsacas Leeuwenb., BESL/ 1: Venezuela, Guyana.
• Vanhouttea Lem., SINN/9: E Brazil.

Diagnostic

Distinguishing characters (always present)

• Inflorescence formed by an indeterminate thyrse with axillary pair-flowered cymes.
• Ovary unilocular with lateral/parietal, T-shaped placentae.

Other important characters

• Anthers often cohering at apex or side by side.

Key differences from similar families

• Stipules never present, leaves never compound (vs. Bignoniaceae with compoubd leaves).
• Latex never present (vs. Campanulaceae which usually has white latex).

Useful tips for generic identification

• See Weber (2004); an addition to this classification was made with the newly recognized tribe Spaerorrhizae (Roalson et al, 2005)

Notable genera and distinguishing features

Achimenes, Gloxinia, Kohleria, Seemannia:

• Flowers mostly reddish or purple.
• Like other members of tribe Gloxinieae they possess perennialscaly rhizomes.

Codonanthe: 

• Flowers white.
• Epiphytic.
• Like many members of tribe Episcieae with fleshy leaves, sometimes growing in ant-gardens, and white flowers.

Columnea:

• Strongly bilabiate and brightly colored corolla representing typical humming-bird flowers.

Nematanthus: 

• Ventricose and brightly colored flowers, often resupinate.

Sinningia: 

•  Usually with well-developed basal tubers.

Literature

Important literature

Roalson, E. H., J. K. Boggan, L. E. Skog. 2005. Reorganization of tribal and generic boundaries in the Gloxinieae (Gesneriaceae: Gesnerioideae) and the description of a new tribe in the Gesnerioideae, Sphaerorrhizae. Selbyana 25: 225-238.

Skog, L. E & Boggan, J, (2006). A new classification of the western hemisphere Gesneriaceae, Gesneriads 3: 12-19.

Souza, V. C & Lorenzi, H. (2008). Botánica sistemâtica, 2nd edition. Instituto Plantarum, Nova Odessa-SP, Brazil., p. 561-565.

Weber, A. in Kubitzki, K. (ed.) (2004), The families and genera of vascular plants, vol. 7, Dicotyledons, Lamiales (except Acanthaceae incl. Avicenniaceae), vol. ed. J. W. Kadereit, Berlin/Heidelberg, Springer, p. 63-158.

Weber, A. & L.E. Skog (2007 onw.): The genera of Gesneriaceae. Basic information with illustration of selected species. Ed. 2.  http://www.genera-gesneriaceae.at/ [website with main features of each genus described; including good illustrations]

For additional illustrations and information on the Gesneriaceae family see "The Gesneriad Reference Web" by Ron Myhr at http://www.gesneriads.ca/

Gesneriaceae, Ian Darbyshire. Flora of Tropical East Africa. 2006

Morphology General Habit

Monocarpic, annual or perennial herbs, rarely shrubs, caulescent or acaulescent

Morphology Leaves

Leaves opposite, pairs equal to unequal, more rarely alternate, sometimes unifoliate with the lamina of cotyledonary origin

Morphology Reproductive morphology Inflorescences

Inflorescences axillary or rarely terminal, cymose, often laxly so, the flowers of each dichotomy paired, occasionally congested and capitate, rarely racemoid

Morphology Reproductive morphology Flowers

Flowers nearly always hermaphrodite, often showy, more rarely cleistogamous with a reduced corolla

Morphology Reproductive morphology Flowers Calyx

Calyx divided to the base into five sepals, or tubular and five-lobed, sometimes the three upper lobes only united

Morphology Reproductive morphology Flowers Corolla

Corolla gamopetalous, tubular, lobes usually 5, imbricate, often arranged in a bilabiate limb

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens usually two or four, rarely five, adnate to the corolla tube.

Morphology Reproductive morphology Flowers Androecium Staminodes

Staminodes present or absent.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers bithecous, opening by longitudinal slits, free or variously connate

Morphology Reproductive morphology Flowers Disc

Disk annular or cupular, often lobed or undulate, occasionally absent

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary superior, unilocular

Morphology Reproductive morphology Flowers Gynoecium Ovary Placenta

Placentation parietal, each placenta bilamellate, these occasionally becoming fused centrally, the capsule then appearing biolocular.

Morphology Reproductive morphology Flowers Gynoecium Ovary Ovules

Ovules numerous

Morphology Reproductive morphology Fruits

Fruit a capsule, often linear, sometimes spirally twisted, or a fleshy berry

Morphology Reproductive morphology Seeds

Seeds numerous, small, ellipsoid or fusiform, sometimes with hair-like appendages at each end; endosperm absent or very slight.

Ecology

They often favour shaded habitats and are frequently epiphytic or lithophytic.

Note

African genera belong to the subfamily Cyrtandroideae and either occur in Asia or have affinity with genera there. They are not closely related to the genera of the Neotropics; characters unique to that region are therefore omitted from the above family description.

Distribution

Range: The African Violet family has some 140 genera (7 in mainland Africa) and approximately 2900 species, mainly in the tropics and subtropics but with a few genera in temperate Eurasia.