1. Begoniaceae C.Agardh

    1. This family is accepted.

[NTK]

Jacques, E.L. & Couto, A.V.S. (2009). Neotropical Begoniaceae.

Morphology
Description

Annual or perennial herbs, shrubs or subshrubs, frequently succulent , erect or climbing, rarely epiphytic ; stems erect or creeping, with rhizomes or tubers, generally fleshy . Leaves alternate , simple , entire or lobed , margins serrate , asymmetric , venation palmate or pinnate ; petiolate , with caducous or persistent stipules. Inflorescences cymous or thyrsoid. Flowers unisexual (plants monoecious or dioecious ), white, pink or reddish. Pistillate flowers slightly zygomorphic , tepals (2-)3-5(6-8) in one whorl, ovary inferior, carpels (1-2)3(4-6), locules (1-2)3(4-6), 1-3(-6)- winged , placentation axile or parietal , placentae bilamellate or entire , styles usually 3, often twisted, united at the base, apically free , stigmas usually 3. Staminate flowers actinomorphic , tepals 2-4(-8) in two whorls, stamens usually numerous, filaments free or fused, anthers with two thecae, dehiscence by longitudinal slits or pores, the connective usually extended beyond the thecae. Fruits usually loculicidal capsules, frequently chartaceous , the mesocarp rarely mucilagionous (Begoniasalesopolensis S.J.Gomes da Silva & Mamede), rarely a berry , wings well-developed or rudimentary, seeds numerous, small (235-)300-600(-1450) µm, with a collar of cells at the microphylar-hilar end, testa brown, ornamented, endosperm absent or if present then represented by a single cell layer, embryo erect , cystoliths sometimes present. 2n = 22, 24, 26, 32, 34, 38, 42 and 48.

Distribution
Distribution in the Neotropics

Begonia L.:

  • Mexico
  • Central America
  • Antilles
  • Colombia
  • Venezuela
  • Trinidad-Tobago
  • Guyana
  • Suriname
  • French Guiana
  • Ecuador
  • Peru
  • Bolivia
  • Brazil

(Steyermark, 1997)

Diagnostic
Distinguishing characters (always present)

The Begoniaceae can be characterized by:

  • An often asymmetric leaf shape.
  • Inferior ovary with axile  placentation.
  • Bifid style.
  • Dry three-wingedfruit.
  • Seeds with a lid and collar cells.
Useful tips for generic identification

Begonia :

  • Inferior ovary.
  • Completely closed ovary.
  • Fruits dehisce between the wings.
  • (2-)3-5 (6-8) pistillate flower tepals.
Notable genera and distinguishing features

Begonia can be characterized by:

  • Often asymmetric leaf shape.
  • Four staminate tepals and five pistillate tepals.
  • Inferior ovary with axile placentation.
  • Dry three-wingedfruit.
  • Seeds with a lid and collar cells.
Key differences from similar families
  • In Datiscaceae fruits dehisce between the styles, pistillate flower tepals are absent in Datiscaceae.
  • In Begoniaceae fruits dehisce between the wings, pistillate flower tepals (2-)3-5(6-8), never absent.
Other important characters
  • Begonia species typically inhabit moist and cloud forest habitats.
  • Succulent herbs.
  • Leaf base one side much broader than the other.
  • Four staminate tepals and five pistillate tepals.  
  • One large capsule wing.
General Description
Number of genera
  • Begonia (1).
Status
  • Native.
General notes
  • Begoniaceae includes the monotypic genus Hillebrandia, distinguished by a semi-inferior ovary, incompletely closed ovary, fruits that dehisce between the styles, and more numerous, more highly differentiated sepals and petals. It is the only member of the family native to the Hawaiian archipelago (Forrest et al. 2005). 
  • The genus Begonia L. (Begoniaceae) has approximately 1,400 named species largely distributed in the tropical and subtropical areas of the world, and within this area is absent only from Australia and Polynesia. It is well represented in Brazil, with approximately 200 species, in almost all ecosystems, except in the mangroves. In Brazil, one of the centers of distribution of the genus is the Atlantic rain forest (Gomes da Silva & Mamede, 2000; Jacques, 1996; Jacques & Mamede, 2004).
Literature
Important literature

De Candolle, A. 1861. Begoniaceae. In  Flora brasiliensis (C.P.F. Martius, ed.). F. Fleischer, Leipzig, v. 3, pars. 1, p. 338-396.

Forrest, L.L. & Hollingsworth, P.M.  2003. A recircumscription of Begonia based on nuclear ribosomal sequences. Plant Systematic and Evolution 241: 193-211.

Forrest, L.L.; Hughes, M. & Hollingsworth, P.M. 2005. A phylogeny of Begonia using nuclear ribosomal sequence data and morphological characters. Systematic of Botany. 30(3): 671-682.

Gomes da Silva, S.J. & Mamede, M.C.H. 2000. A new species of Begonia (Begoniaceae) from the Atlantic Coastal Forest in the State of São Paulo, Brazil. Novon 10: 22-25.

Irmscher, E. Begoniaceae. In (A. Engler & K. Prantl, eds.) Die natürlichen Pflanzenfamilien. 2 ed. v. 21, p. 548-588.

Jacques, E.L. 1996. Begoniaceae. In: Lima, M.P.M. & Guedes-Bruni, R.R. (eds.). Reserva Ecológica de Macaé de Cima, Nova Friburgo, RJ - Aspectos Florísticos das Espécies Vasculares - Volume 2: 93-133. Jardim Botânico do Rio de Janeiro, Rio de Janeiro.

Jacques, E.L. 2002. Estudos taxonômicos das espécies brasileiras do gênero Begonia L. (Begoniaceae) com placenta partida. Tese de Doutorado. Instituto de Biociências. Universidade de São Paulo.

Jacques, E.L. & Mamede, M.C.H. 2004. Novelties in Begonia (Begoniaceae) from the coastal forests of Brazil. Brittonia 56(1): 75-81.

Jacques, E.L. & Mamede, M.C.H. 2005. Notas nomenclaturais em L. (Begoniaceae) Revista Brasileira de Botânica 28: 579-588.

Steyermark, J.A.  1997. Begoniaceae in Flora of Venezuelan Guayana. v. 3: p. 397-403.

Warburg, O. 1894. Begoniaceae. In (A. Engler & K. Prantl, eds.) Die natürlichen Pflanzenfamilien. Leipzig: Wilhelm Engelmann, v. 3, n. 6a, p. 121-150.

[FWTA]

Begoniaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954

Habit
Herbs or undershrubs, mostly succulent
Leaves
Leaves alternate, simple, often unequal-sided or oblique; stipules free, deciduous
Flowers
Flowers monoecious, actinomorphic or asymmetric, mostly in axillary cymes, showy Male flower: sepals 2, opposite, rarely 5, valvate; petals imbricate or absent; stamens numerous, filaments free or connate, anthers 2-celled, continuous with the filament, opening lengthwise Female flower: perianth more or less as in the male; staminodes absent or very small; ovary inferior, 2–4- (rarely 1-) celled, mostly angled or winged; styles 2–5, free or connate; stigmas often twisted, papillose all over; ovules very numerous, on axile projecting simple or lobed placentas
Male
Male flower: sepals 2, opposite, rarely 5, valvate; petals imbricate or absent; stamens numerous, filaments free or connate, anthers 2-celled, continuous with the filament, opening lengthwise
Female
Female flower: perianth more or less as in the male; staminodes absent or very small; ovary inferior, 2–4- (rarely 1-) celled, mostly angled or winged; styles 2–5, free or connate; stigmas often twisted, papillose all over; ovules very numerous, on axile projecting simple or lobed placentas
Fruits
Fruit a capsule or berry
Seeds
Seeds minute and very numerous, with reticulate testa, scanty or no endosperm and straight embryo
[FZ]

Begoniaceae, F. K. Kupicha. Flora Zambesiaca 4. 1978

Habit
Herbs or subshrubs, usually fleshy
Leaves
Leaves alternate, simple or very rarely pinnate, often asymmetric; stipules free, persistent or deciduous
Flowers
Flowers monoecious, actinomorphic or zygomorphic, in terminal or axillary cymes, conspicuous; sepals and petals usually not distinguished male flower: tepals 2–5, free or connate; stamens ?, filaments free or rarely connate; anthers 2-celled, continuous with the filament, opening lengthwise or rarely by apical pores; rudimentary gynoecium absent female flowers: tepals ± as in male, rarely 6–9; staminodes absent or very small; ovary inferior, (1)2–4(6)-celled, usually angled or winged; styles 2–6, free or connate, usually bifid but occasionally multifid, branches stigmatic and often twisted; placentation axile or rarely (Hillebrandia) parietal, placentae entire or lobed; ovules very numerous
Male
male flower: tepals 2–5, free or connate; stamens ?, filaments free or rarely connate; anthers 2-celled, continuous with the filament, opening lengthwise or rarely by apical pores; rudimentary gynoecium absent
Female
female flowers: tepals ± as in male, rarely 6–9; staminodes absent or very small; ovary inferior, (1)2–4(6)-celled, usually angled or winged; styles 2–6, free or connate, usually bifid but occasionally multifid, branches stigmatic and often twisted; placentation axile or rarely (Hillebrandia) parietal, placentae entire or lobed; ovules very numerous
Fruits
Fruit a capsule or berry; seeds minute and very numerous, with reticulate testa, little or no endosperm and straight embryo
[FTEA]

Begoniaceae, Vanessa Plana, Martin J.S. Sands & Henk J. Beentje. Flora of Tropical East Africa. 2006

Habit
Herbs, subshrubs or sometimes shrubs, monoecious or very rarely dioecious, usually perennial, terrestrial or epiphytic.
Stem
Stems herbaceous, sometimes succulent, woody, erect, reclinate, rhizomatous or tuberous (then acaulescent or shortstemmed), rarely a liane or climbing with adventitious roots.
Leaves
Leaves whorled in acaulescent species, otherwise usually alternate, more rarely distichous or opposite, stipulate (stipules persistent or caducous), petiolate, sometimes subsessile, occasionally peltate, usually asymmetric, the broader side often with enlarged basal lobe, but sometimes symmetric, entire to deeply dissected or palmately compound; glabrous or with simple or stellate hairs, sometimes with scaly trichomes; venation palmate, palmate-pinnate or pinnate.
Bulbils
Leaf-axil bulbils sometimes present.
Inflorescences
Inflorescence axillary or terminal, androgynous or unisexual, usually cymose but sometimes racemose or compound, protandrous or protogynous.
Bracts
Bracts persistent or not; bracteoles often present (but rare in African species).
Flowers
Male flowers with 2 or (3–)4(–10) free or variably fused tepals; stamens 3–many in an actinomorphic or zygomorphic cluster; filaments free or variably fused into a column; anthers always yellow (in our area), 2-celled, opening lengthwise or by short apical slits or pores, the connective sometimes extended (rare in Africa). Female flowers with 2–6(–10) often unequal tepals, free or partially fused; ovary inferior, or semi-inferior in Hillebrandia, broadly obovoid to globose or fusiform, with (1–)3(–7) wings or horns, more rarely wingless, (1–)2–3(–6)-locular; placentation axillary or occasionally parietal or septal, in cross-section the placentas entire or with 2(–4) branches, rarely the inner-facing surfaces devoid of ovules (as in sect. Squamibegonia); styles (2–)3–4(–7), persistent or caducous, free or partly connate, usually forked, sometimes more than once, the stigmatic tissue usually in a continuous spiral band, sometimes kidney-shaped or rarely occurring all over the style (in our area in sect. Squamibegonia). Flowers usually white or pink, unisexual, tepals in 1 or 2 ( Hillebrandia) distinct whorls.
Fruits
Fruit erect, pendulous or nodding, most commonly a capsule, the wings (or horns) subequal, unequal or differing in size and shape, more rarely (but fairly frequently in Africa) baccate or fleshy; usually dehiscent, usually loculicidally (or in Hillebrandia in between the styles), more rarely (especially in species with wingless fruits) indehiscent or dehiscing irregularly.
Seeds
Seeds numerous, minute, with collar cells, little or no endosperm and reticulate testa.

Images

Begoniaceae C.Agardh appears in other Kew resources:

First published in Aphor. Bot. 200. 1824 [13 Jun 1824] (1824)

Accepted by

  • APG IV (2016) http://dx.doi.org/10.1111/boj.12385

Sources

Flora Zambesiaca
Flora Zambesiaca
http://creativecommons.org/licenses/by-nc-sa/3.0

Flora of Tropical East Africa
Flora of Tropical East Africa
http://creativecommons.org/licenses/by-nc-sa/3.0

Flora of West Tropical Africa
Flora of West Tropical Africa
http://creativecommons.org/licenses/by-nc-sa/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Neotropikey
Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.
http://creativecommons.org/licenses/by/3.0