Introduction

Detarioideae comprises 79 genera and c. 760 species, almost exclusively tropical with species present on all continents. Even though historically considered as two tribes, the monophyly of this group has been clearly demonstrated in all phylogenetic analyses and the generic content of Detarioideae has remained relatively stable since the mid-1800. Currently six tribes are recognised within Detarioideae: Afzelieae, Amherstieae, Barnebydendreae, Detarieae, Saraceae and Schotieae.

The subfamily is unusual in including many monospecific genera (35%) and only 9 genera with more than 20 species. Detarioideae is differentiated from other subfamilies by the presence of intrapetiolar stipules and well developed bracteoles that are imbricate or valvate in bud, and which often serve a protective function. However, the floral morphology is extremely variable and, in many taxa, highly modified with striking differences in floral symmetry, sepal, petal, and stamen numbers, and fusion and suppression of floral organs. The subfamily includes large tree species that predominate in wet forest habitats of the African, American, and Asian tropics, but they also form ecologically dominant elements in other habitat types (e.g., Brachystegia-dominated Miombo dry forests of East Africa).

Although several fossils have been attributed to Detarioideae, including some remarkable flower, fruit and wood fossils preserved in amber, the age of the subfamily remains contentious with crown age estimates ranging from early Paleocene to mid-Eocene.

Key Features

Detarioideae are medium to tall unarmed trees, or sometimes shrubs. Specialised extrafloral nectaries are often present on the underside of the leaflets or leaf rachis (but they are never found on the petiole). Stipules in Detarioideae are distinct in occurring in an intrapetiolar position. The leaves are commonly paripinnate, but sometimes unifoliate and rarely simple. Detarioideae are often recognised by their large, frequently petaloid bracteoles that can serve a protective and attraction function, but they can also be small. The flowers are variable (but never papilionate), usually with five sepals but with the two adaxial sepals often fused so that the calyx appears four-merous. The petals are free and vary in number from one to five, but they can also be absent. Usually 10 stamens are present (the number can vary) and staminodes are occasionally present. The fruits are mostly woody dehiscent pods, or sometimes they are indehiscent and samaroid.

Distribution and ecology

Species of Detarioideae are almost exclusively tropical, except for Schotia Jacq., which occurs in sub-tropical South Africa. Detarioideae occur mostly in the tropical Rainforest biome but some species are native to the Succulent biome. Despite its pantropical distribution, the majority of Detarioideae generic and species diversity occurs in Africa and Madagascar (58% of genera and c. 330 spp). Detarioideae include many ecologically important tree species in African rainforests and in lowland wet forests of the Neotropics. Some Detarioideae species form large stands and are the dominant species in different forest types. In contrast, in Asian tropical dipterocarp-dominated rainforests, although present, Detarioideae are low in abundance and diversity.

Human uses

Many members of the subfamily are of economic importance for their gums and resins (Hymenaea), oils (Copaifera), food (Tamarindus), timbers, and ornamentals. Plants of this subfamily provide timber (e.g. Aphanocalyx, Berlinia, Didelotia, Hymenaea, Peltogyne and Tetraberlinia), some of which are highly valuable (e.g., species of Guibourtia), several species are the source of useful resins (e.g. Copaifera, Hymenaea), and Tamarindus is used as a condiment for cooking. Some species are also part of cultural heritage, used for rituals and medicine or seen as holy trees (e.g. several species of Brownea and Copaifera religiosa).

Formal Botanical Description

As published in LPWG (2017), Taxon 66: 44-77, doi.org/10.12705/661.3

Subfam. Detarioideae Burmeist., Handb. Naturgesch.: 319. 1837 (“Detarieae”)

Type: Detarium Juss.

Unarmed trees, sometimes shrubs, rarely suffruticose (Cryptosepalum Benth.); specialised extrafloral nectaries often present abaxially, rarely on the margins of leaflets or on leaf rachis, and never on the petiole. Stipules in intrapetiolar position (i.e., somewhere between the petiole and the axillary bud) and then free, valvate and connected by chaffy hairs, or fused, either partly (only at base) or entirely, rarely lateral and free. Leaves paripinnate (ending in a pair of leaflets or, if leaflets alternate and appearing imparipinnate, the terminal leaflet exceeded by a more or less caducous rachis-extension) with 1 (bifoliolate) to numerous pairs of leaflets, or rarely unifoliolate (Paloue Aubl., Zenkerella Taub., some Cryptosepalum, Didelotia Baill. and Guibourtia Benn.), bipinnate leaves totally lacking, leaves pulvinate, leaflets opposite or alternate, exstipellate, translucent glands sometimes present. Inflorescence a raceme or panicle; bracteoles small to large, frequently petaloid, valvate or imbricate, free or partially fused or partly fused with the hypanthium, partially or completely enclosing the bud. Flowers bisexual or with both bisexual and male flowers radially or slightly to strongly bilaterally symmetrical (but never papilionate), hypanthium elongated to almost absent; sepals commonly 5 or 4 (two adaxial sepals often fused), rarely some or all absent or more (–7); petals free, 0–5(–7), when present imbricate, the adaxial petal generally innermost (outermost in some flowers of Hymenaea L. and allies), all equal or the adaxial large and either the other 4 or only the abaxial ones smaller to rudimentary; stamens 2–numerous but usually 10, the filaments partly connate or free, staminodes occasionally present; anthers dorsifixed or basifixed; pollen mostly 3-colporate monads with a vast array of sculptures; gynoecium 1-carpellate, 1–many ovulate, stipe of ovary free or adnate to the wall of the hypanthium. Fruits mostly woody, dehiscent pods, sometimes indehiscent and woody or thin-valved, samaroid (Brandzeia Baill., Barnebydendron J.H.Kirkbr., Gossweilerodendron Harms, Hardwickia Roxb., Neoapaloxylon Rauschert), rarely filled with pulpy mesocarp (Tamarindus L.) or endocarp (Hymenaea). Seeds often overgrown, sometimes hard and then occasionally with pseudopleurograms (Lysidice Hance, Paramacrolobium J.Léonard, Peltogyne Vogel, Tamarindus), occasionally arillate; embryo straight. Vestured pits present in secondary xylem; axial (resin) canals sometimes present; silica bodies rarely present (Hymenostegia Harms, Loesenera Harms); septate fibres and storeyed rays sometimes present. Root nodules absent. 2n mostly 24 but occasionally 16, 20, 22, 36, 68. Coumarins reported; frequently with terpenes (resins) and non-protein amino acids.

To learn more

Bruneau, A., Klitgård, B., Prenner, G., Fougère-Danezan, M., Tucker, S.C. 2014. Floral evolution in the Detarieae (Leguminosae): phylogenetic evidence for labile floral development in an early-diverging legume lineage. International Journal of Plant Sciences 175, 392–417. doi: 10.1086/675574

Estrella, M., Forest, F., Klitgård, B., Lewis, G.P., Mackinder, B., de Queiroz, L., Wieringa, J. & Bruneau, A. 2018. A new phylogeny-based tribal classification for the Detarioideae, an early-branching clade of florally diverse legumes. Scientific Reports 8(1), 6884. doi: 10.1038/s41598-018-24687-3

Estrella, M., Forest, F. Wieringa, J.J., Fougère-Danezan, M. & Bruneau, A. 2017. Insights on the evolutionary origin of Detarioideae, a clade of ecologically dominant tropical African trees. New Phytologist 214: 1722-1735. doi: 10.1111/nph.14523

Fougère-Danezan, M, S Maumont & A Bruneau. 2007. Relationships among resin producing Detarieae s.l. (Leguminosae) as inferred by molecular data. Syst Bot 32:748–761.

Fougère-Danezan, M, PS Herendeen, S Maumont & A Bruneau 2009. Morphological evolution in the variable resin-producing Detarieae (Leguminosae): do morphological characters retain a phylogenetic signal? Ann Bot 105:311–325.

Léonard, J. 1957. Genera des Cynometreae et des Amherstieae Africaines (Leguminosae-Caesalpinioideae). Mem Acad R Belg Cl Sci 30:1–314.

Mackinder, BA 2005 Tribe Detarieae. Pages 68–109 in G Lewis, B Schrire, B Mackinder, M Lock, eds. Legumes of the world. Royal Botanic Gardens, Kew.

List of genera

Below is an alphabetical list of all genera accepted by the LPWG with links out to the taxonomic pages on our portal, GBIF and World Checklist of Vascular Plants (Kew). Over time this list will be updated to reflect the evolving taxonomy.

Please see the Species List and Synonyms and Legume Taxonomy Working Group pages for more taxonomic information. The current taxonomy is accessbile by Browse or Advanced Search.