1. Combretaceae R.Br.

    1. This family is accepted.

[FTEA]

Combretaceae, G. E. Wickens. Flora of Tropical East Africa. 1973

Habit
Trees, shrubs, shrublets or climbers, very rarely subherbaceous
Indumentum
Indumentum of unicellular compartmented (very rarely non-compartmented) hairs, multicellular stalked glands and multicellular scales (in which the head consists of a multicellular plate only one cell thick)
Leaves
Leaves opposite, verticillate, spiral or alternate, exstipulate, simple and almost always entire (very rarely crenulate)
Flowers
Flowers hermaphrodite or hermaphrodite and ? in the same inflorescence, usually 4–5-merous, rarely slightly zygomorphic, in axillary or extra-axillary spikes or racemes or in terminal or axillary panicles
Receptacle
Receptacle (calyx-tube or hypanthium) usually in 2 distinct parts, the lower receptacle surrounding and adnate to the inferior (except in Strephonema from West Africa) ovary and the upper receptacle usually produced beyond it to form a short or long tube terminating in the sepals (calyx-lobes), the latter sometimes scarcely developed
Calyx
Sepals 4 or 5 (rarely 6 or 8) or almost absent, sometimes accrescent >i>(Calycopteris in Asia)
Corolla
Petals 4 or 5, conspicuous to very small, or absent, usually inserted near the mouth of the upper receptacle
Androecium
Stamens usually twice as many as the sepals or petals (occasionally the same number, but not inE. Africa), biseriate or more rarely uniseriate, exserted or included in the upper receptacle; anthers versatile (rarely adnate to the filaments but not inE. Africa)
Nectaries
Disk intrastaminal, hairy or glabrous, sometimes inconspicuous or absent
Gynoecium
Style usually free (attached to the upper receptacle for part of its length in >i>Quisqualis and a very few species of >i>Combretum); ovary inferior (semi-inferior in >i>Strephonema), 1-locular with usually 2 (up to 6) pendulous anatropous ovules of which only 1 usually develops
Fruits
Fruit very variable in size and shape, fleshy or dry, stipitate or sessile, usually indehiscent, often variously winged or ridged, 1-seeded
Seeds
Seeds without albumen Cotyledons 2 (rarely 3), occasionally with their petioles connate almost to the apex
[FZ]

Combretaceae, A. W. Exell. Flora Zambesiaca 4. 1978

Habit
Trees, shrubs, shrublets or climbers, rarely subherbaceous
Indumentum
Indumentum of unicellular compartmented (rarely non-compartmented) hairs, multicellular stalked glands and multicellular scales (in which the head consists of a multicellular plate only one cell thick)
Leaves
Leaves opposite, verticillate, spiral or alternate, exstipulate, simple and almost always entire (very rarely crenulate)
Flowers
Flowers bisexual or bisexual and male in the same inflorescence or very rarely dioecious, usually 4–5-merous, rarely slightly zygomorphic, in axillary or extra-axillary elongated or subcapitate spikes or racemes or in terminal or axillary panicles
Receptacle
Receptacle (calyx-tube or hypanthium) usually in two distinct parts, the lower receptacle surrounding and adnate to the inferior (except in Strephonema from West Africa) ovary and upper receptacle usually produced beyond it to form a short or long tube (perhaps a true calyx-tube in Meiostemon) terminating in the sepals (calyx-lobes), the latter sometimes scarcely developed
Calyx
Sepals 4 or 5 (rarely 6 or 8) or almost absent, sometimes accrescent (Calycopteris in Asia)
Corolla
Petals 4 or 5 (rarely more) or absent, conspicuous or sometimes very small, usually inserted near the mouth of the upper receptacle (but near the disk in Meiostemon)
Androecium
Stamens usually twice as many as the sepals or petals but occasionally the same number (4 in Meiostemon), borne inside the upper receptacle with biseriate or more rarely uniseriate insertion (one whorl very rarely as staminodes), exserted or included; anthers dorsifixed, versatile (rarely adnate to the filaments, but not in our area)
Nectaries
Disk intrastaminal, hairy or glabrous, sometimes inconspicuous or absent
Gynoecium
Ovary inferior (semi-inferior in Strephonema), 1-locular with usually 2 (up to 6) pendulous anatropous ovules of which only 1 usually develops Style usually free (attached to the upper receptacle for part of its length in Quisqualis and a very few species of Combretum)
Fruits
Fruit (a pseudocarp) very variable in size and shape, fleshy or dry, stipitate or sessile, usually indehiscent (occasionally tardily dehiscent) often variously winged or ridged, 1-seeded
Seeds
Cotyledons 2 (rarely 3 or 4) occasionally with their petioles connate almost to the apex Albumen absent
[NTK]

Loiola, M.I.B. (2009). Neotropical Combretaceae.

Morphology
Description

Trees or shrubs often scandent (Combretum Loefl.), mesophytic, xerophytic or halophytic (Laguncularia C.F.Gaertn.), with long, straight, sharply-pointed, unicellular trichomes with very thick walls and with a conical internal compartment at the base (Combretaceous hairs), and with or without stalked glands or glandular scales. Stipules absent. Leaves opposite, alternate , rarely whorled , simple , petiolate , venation pinnate , margins entire . Inflorescences spicate, racemose or paniculate, sometimes globular clusters (Conocarpus L.), terminal or axillary . Flowers usually small, actinomorphic or zygomorphic , bisexual , sometimes unisexual (plants monoecious or polygamous, and rarely dioecious in Conocarpus), 4-5 merous , with hypanthium divided into two regions, a lower surrounding the ovary and an upper narrowed into a shorter or longer tube finished in calyx lobes; bracteoles absent or when present adnate to the hypanthium; calyx lobes usually 4 or 5, connate , sometimes inconspicuous, imbricate to valvate ; petals usually 4-5 or absent, small, alternisepalous, imbricate to valvate ; androecium usually with 8-10 stamens, commonly in 2 whorls alternating with and opposite the corolla members; filaments long- exserted (Combretum) or included; anthers dorsifixed, versatile or adnate to the filaments (Buchenavia Eichler), dehiscing longitudinally; gynoecium syncarpous, ovary inferior semi-inferior (Strephonema Hook.f.), unilocular, with apical placentation, 2-6 ovules pendulous, non-arillate, anatropous, with long funicle; style simple , usually filiform , free or partially adnate to the upper part of hypanthium, stigma minute, punctate or capitate ; nectary usually an intrastaminal disk at the base of hypanthium, disk sometimes absent. Fruits usually indehiscent , rarely dehiscent (in introduced Quisqualis indica Blanco), drupaceous , samararoid or rarely a capsule , often 2-5- winged or -ridged or -angled, with pericarp lignified or not lignified, fleshy (Buchenavia) or dry. Seed 1, non-endospermic; embryo with convolute or plicate cotyledons and small radicle.

Distribution
Distribution in the Neotropics
  • Buchenavia Eichler - Mesoamerica, Caribbean, South America.
  • Combretum Loefl - Mexico, Mesoamerica, Caribbean, South America.
  • Conocarpus L. - Mexico, Mesoamerica, Peru, Ecuador, Brazil.
  • Laguncularia Gaertn - Mexico, Mesoamerica, Caribbean, Colombia, Peru, Ecuador, Brazil.
  • Quisqualis L. - (Q. indica introduced from Africa and cultivated).
  • Terminalia L. - Mexico, Mesoamerica, South America.
Diagnostic
Key differences from similar families
  • Apical placentation (axillary in Onagraceae and Lythraceae).
Notable genera and distinguishing features

Combretum:

  • Leaves opposite.
  • Petals 4 or absent.
  • Stamens 4 or 8.
  • Fruit 4-winged.

Terminalia:

  • Leavesalternate or verticillate.
  • Petals absent.
  • Stamens 10.
  • Fruit 2-5-winged.
Useful tips for generic identification

Key to genera of Neotropical Combretaceae

1. Flowers conspicuous; petals more than 10 mm; stamens included in calyx tube ... Quisqualis
1. Flowers small; petals less than 10 mm; stamens exserted or included in calyx tube ... 2

2. Inflorescences globular clusters ; fruit aggregated ... Conocarpus
2. Inflorescence spicate, racemose or paniculate; fruit not aggregated ... 3

3. Lowers receptacle with 2 adnate bracteoles ... Laguncularia
3. Lowers receptacle without adnate bracteoles ... 4

4. Anthers adnate to the filaments ... Buchenavia
4. Anthers versatile ... 5

5. Leaves opposite; trees or shrubs often scandent ... Combretum
5. Leaves alternate or verticillate; trees ...Terminalia

Other important characters
  • Presence of stalked glands or glandular scales.
  • Flowers usually small.
Distinguishing characters (always present)
  • Leaves simple, entire, petiolate.
  • Ovary inferior.
  • Hypanthium divided into two regions (a lower surrounding the ovary and an upper narrowed into a shorter or longer tube finished in calyx lobes).
  • Trichomes long, straight, sharply-pointed, unicellular, with very thick walls and with a conical internal compartment at the base.
General Description
Number of genera

6 genera:

  • Buchenavia
  • Combretum
  • Conocarpus
  • Laguncularia
  • Quisqualis 
  • Terminalia
Status
  • Buchenavia (native).
  • Combretum (native, cultivated).
  • Conocarpus (native).
  • Laguncularia (native).
  • Terminalia (native, cultivated).
  • Quisqualis (introduced and cultivated).
Notes on delimitation
  • Combretaceae was traditionally placed in the order Myrtales and analyses based on molecular characters identifies it as the sister clade to the rest of the order.
  • Morphology and rbcL sequence characters both support the monophyly of Combretaceae.
General notes
  • The family stands out economically for its ornamental value, with some species commercialized by florists worldwide.
  • Others are cited in the literature as having pharmacological potential and being widely used as popular diuretics or antipyretics. A number of species exhibit antimicrobial, antihemorrhagic and antiulcer activities.
  • Conocarpus erectus L. and Laguncularia racemosa (L.) Gaertn. are typical of mangrove areas and are ecologically essential to the dynamics of this ecosystem and to the survival of its organisms. 
  • Lagunculariaracemosa shows several adaptations to daily flooding by salt water: the leaves contain salt excretory glands, the seeds germinate while still attached to the tree (vivipary), and the roots include pneumatophores.
Literature
Important literature

Brummitt, R. K. 1992. Vascular plants families and genera. Royal Botanic Gardens, Kew. 733pp.

Conti, E.,  Litt, A., Wilson, P. G., Graham, S. A., Briggs, B. G.,  Johnson, L. A. S. & Sytsma, K. J. 1997. Interfamilial Relationships in Myrtales: Molecular Phylogeny and Patterns of Morphological Evolution. Systematic Botany 22 (4): 629-647.

Exell, A. W. & Stace, C. A. 1966. Revision of the Combretaceae. Boletim da la Sociedad Broteriana. sér.2, 40: 5-25.

Loiola, M. I. B. & Sales, M. F. de. 1996. Estudos taxonômicos do gênero Combretum Loefl. (Combretaceae R. Br.) em Pernambuco - Brasil. Arquivos do Jardim Botânico do Rio de Janeiro 34(2): 174-188.

Marquete, N. F. da S. & Valente, M. C. 2005. Flora da Reserva Ducke, Amazonas, Brasil: Combretaceae. Rodriguésia 56 (86): 131-140. 2005.

Stace, C. A. 1980. The significance of the leaf epidermis in the taxonomy of the Combretaceae: conclusions. Botanical Journal of the Linnean Society. London 81: 327-339.

Stace, C. A. Combretaceae. 2007. In: G. Harling & C. Person (eds.), Flora of Ecuador 81: 1-63.

Sytsma, K.J., A. Litt, M.L. Zjhra, J.C. Pires, M. Nepokroeff, E. Conti, Jay Walker, and P.G. Wilson. 2004. Clades, clocks, and continents: historical and biogeographical analysis of Myrtaceae, Vochysiaceae, and relatives in the southern hemisphere. International Journal of Plant Sciences 165 (4 Suppl.): 85-105.

Tan, F., Shi, S., Zhong, Y., Gong, X. & Wang, Y. 2002. Phylogenetic relationships of Combretoideae (Combretaceae) inferred from plastid, nuclear gene and spacer sequences. Journal of Plant Research 15(6): 475-481.

[FWTA]

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

Habit
Trees or shrubs, often scandent
Leaves
Leaves opposite, alternate or rarely verticillate, simple, exstipulate
Flowers
Flowers spicate or racemose, mostly small, hermaphrodite, rarely unisexual
Calyx
Calyx-tube adnate to the ovary; limb 4–8-fid or -lobed, lobes valvate
Corolla
Petals 4–5 or none, rarely many, small, imbricate or valvate
Androecium
Stamens 4–10, rarely more; filaments inflexed in bud; anthers versatile, didymous, opening lengthwise by slits
Nectaries
Disk epigynous
Gynoecium
Ovary inferior, rarely half-inferior, 1-celled; style simple; ovules 2–6, suspended from the apex of the ovary by slender funicles
Fruits
Fruit often winged, rarely dehiscent
Seeds
Seed pendulous, without endosperm; embryo with convolute, plicate or contorted cotyledons and small radicle

Images

Combretaceae R.Br. appears in other Kew resources:

First published in Prodr. [A. P. de Candolle] 351. 1810 [27 Mar 1810] (1810)

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 2018. 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

Plants and People Africa
Common Names from Plants and People Africa http://www.plantsandpeopleafrica.com/
© Plants and People Africa http://www.plantsandpeopleafrica.com http://creativecommons.org/licenses/by/3.0/