The Genera of Leguminosae-Caesalpinioideae and Swartzieae


L. Watson and M. J. Dallwitz


In the following group descriptions, a number in parentheses indicates the number of genera exhibiting a character state. This number may be followed by a slash and another number indicating the number of genera for which the character is recorded (and applicable). For example, (7/26) indicates that 7 genera exhibit the character state, out of the 26 genera for which data on the character are recorded.


Swartzieae (11 genera)

Trees (11 genera), shrubs (6 genera), rarely lianas (1). Leaves sometimes unifoliolate or simple (6 genera); otherwise pinnate (8 genera), then usually imparipinnate (7/8); the leaflets petiolulate, stipels sometimes present. Stomata paracytic (3 genera) or not (6 genera), abaxial epidermal walls straight; with (4) or without (5) transcurrent veins; druses absent from the mesophyll (9/9), phloem transfer cells absent. Wood storied (10/10). Inflorescences racemose, racemose-paniculate or flowers solitary. Flowers not pentamerous; calyx entire in bud, opening irregularly into segments or into regular lobes; corolla of 0–5 petals, sometimes with vestigial petals; where ascertainable, corolla usually imbricate-descending (papilionaceous; 6/7). Staminodes absent; stamens usually 10 or more, usually (10/11) equal, free or (rarely) cohering via hairs; anthers basifixed (7) or dorsifixed (5). Ovary usually stipitate (10/11); seeds sometimes arillate (3/8), with starch, no amyloid, radicle inflexed. Mainly South American (9 genera) and African (4 genera).

Aldina, Baphiopsis, Bocoa, Candolleodendron, Cordyla, Exostyles, Harleyodendron, Lecointea, Mildbraediodendron, Swartzia, Zollernia


I. Caesalpinieae sensu lato (49 genera)

Trees or shrubs (a few scandent), sometimes armed with prickles or spines. Leaves pinnate or (30 genera) bipinnate, with spiral phyllotaxy; often (19) with non-paracytic stomata, no hairs with expanded/embedded feet, nearly always without conspicuous phloem transfer cells in the minor veins, mesophyll hardly ever exhibiting secretory cavities. Stipules (where present and recorded) interpetiolar. Wood infrequently storied (7/26).

Inflorescences not cymose. Bracteoles often (35) lacking. Flowers often pentamerous through calyx, corolla and androecium. Calyx polysepalous to gamosepalous, regular to very zygomorphic, often (20) not imbricate; corolla present, actinomorphic to zygomorphic but rarely with vestigial petals. Androecial members usually 10, nearly always all free (48), anthers usually dorsifixed, dehiscing by lateral to introrse slits. Pollen often with a margocolpus (11/30), the tectum nearly always punctate or reticulate. Disc nearly always absent. Ovary usually (43) central and free.

Seeds endospermic (23) or not, amyloid absent. Cotyledons mostly of types 2 or 3. Basic chromosome numbers often 13 or 14 (16 genera), less often 12 (9 genera).

More genera in South America (29) than in Africa (21), and with stronger representation than Detarieae (tribe IV) in Madagascar.

Subgroup 1 (21 genera)

Trees or (often) shrubs, occasionally scandent, not infrequently armed. Leaves with rachides adaxially grooved or (more often) not; leaflets often many, those of pinnate leaves opposite or alternate, often sessile; abaxial epidermis usually scarcely staining with safranin, capitate glandular hairs sometimes present, stomata usually not paracytic; hardly ever exhibiting transcurrent veins, the minor veins often without sclerenchyma, druses nearly always present in the mesophyll. Floral tube tending to be relatively shorter than in subgroup 4 (usually polysepalous, the segments free to the rim of the hypanthium); calyx often not imbricate, usually covering the petals in bud. Calyx and corolla usually very irregular. Fruit a two-valved pod or (often) indehiscent, often winged.

Acrocarpus, Aprevalia, Bussea, Caesalpinia, Cercidium, Colvillea, Conzattia, Cordeauxia, Delonix. Hoffmanseggia, Lemuropisum, Lophocarpinia, Mezoneuron, Moldenhauera, Parkinsonia, Peltophorum, Pterolobium, Stenodrepanum, Stuhlmannia, Wagatea, Zuccagnia

Subgroup 2 (4 genera)

Intermediate between subgroups 1 and 4, but usually with short-shoots, sometimes two to several superimposed axillary buds (2/2), bipinnate leaves, small unisexual and usually non-pentamerous flowers; 3-6 sepals and petals, calyx not covering corolla in bud, 4-12 stamens, fruit often indehiscent or dehiscing atypically, seeds endospermic.

Arcoa, Gleditsia, Gymnocladus, Tetrapterocarpon

Subgroup 3 (1 genus)

Intermediate between subgroups 1 and 4, characterised by a peculiar gynoecium and fruit, and 2n = 20.


Subgroup 4 (23 genera)

Mainly trees, less often (6 genera) shrubs, unarmed (except sometimes in Haematoxylum and Arcoa). Leaves nearly always with adaxially grooved rachides; the leaflets often few, those of pinnate leaves generally opposite, petiolulate; abaxial epidermis nearly always clearly staining with safranin, without capitate trichomes, the stomata paracytic; the minor veins with sclerenchyma, sometimes with trans- current veins, druses nearly always absent from the mesophyll. Floral tube tending to be relatively longer than in subgroup 1, the calyx often gamosepalous above the rim of the hypanthium; calyx imbricate, often not covering the corolla in bud; calyx and corolla mostly regular to slightly irregular. Fruit a two-valved pod, less often indehiscent, sometimes a follicle; not winged.

Arapatiella, Batesia, Burkea, Campsiandra, Cenostigma, Chidlowia, Dimorphandra, Diptychandra, Erythrophloeum, Haematoxylum, Jacqueshuberia, Kaoue, Melanoxylon, Mora, Pachyelasma, Recordoxylon, Schizolobium, Selerolobium, Stachyothyrsus, Stahlia, Sympetalandra, Tachigalia, Vouacapoua

II. Cercideae (Bauhinieae) (11 genera)

Trees or shrubs, lianas or vines, with or without tendrils. Leaves bifoliolate with sessile leaflets, or simple to bilobed (often mucronate between the lobes), phyllotaxy spiral or distichous. Stomata usually paracytic (5/6), abaxial epidermal walls nearly always straight; the minor bundles accompanied by sclerenchyma, usually (7/8) having transcurrent veins; minor veins without phloem transfer cells; druses usually (8/8) present in the mesophyll. Wood storied (313).

Gamosepalous, the calyx open or closed apically before anthesis, entire, dentate, spathaceous or valvately 2–5 lobed. Hypanthium present or absent. Corolla slightly to very zygomorphic (absent in Brenierea). Androecium parts 10 (rarely fewer), usually unequal (9/10), staminodes present (6/11) or absent, the filaments partially connate or not, anthers versatile. Ovary stipitate, adnate to hypanthium or free.

Seeds usually (8/10) endospermic, without amyloid, often (8/10) arillate.

Basic chromosome numbers 13 (2 genera), 14 (5 genera), and 7 (1 genus).

Taxa best included in Bauhinia (cf. Wunderlin, Larsen and Larsen 1981) in parentheses:

Adenolobus, (Barklya), Bauhinia, (Bracteolanthus), Brenierea, Cercis, Griffonia, (Lasiobema, Lysiphyllum, Phanera, Piliostigma)

III. Cassieae (20 genera)

Trees, shrubs (occasionally climbing) or herbs. Leaves usually imparipinnate (15 genera), sometimes unifoliate (6), rarely phyllodes; phyllotaxy spiral or distichous; petiolules not twisted; abaxial epidermis often scarcely staining with safranin (9/15), stomata usually paracytic (10/14), hooked trichomes often (12/14) and epidermal crystals sometimes (6/16) present, hairs with expanded/embedded feet absent, adaxial interveinal epidermal walls usually straight. Mesophyll without secretory cavities; druses sometimes present (4 genera), usually absent; the minor veins accompanied by fibres (15/15), transcurrent veins often present (10/14), phloem of minor veins with or without conspicuous transfer cells. Wood often storied (7/9).

Inflorescence often cymose (16), bracteoles present. Flowers not pentamerous through calyx, corolla and androecium; calyx imbricate, hypanthium absent or very short; androecium parts usually fewer than 10 (17 genera), rarely more (2 genera), staminodes present; filaments nearly always attached at base of connective (and anthers non-versatile), anther dehiscence often via basal or apical pores (14 genera); intrastaminal disc sometimes present.

Seeds usually non-endospermic (8/10), without amyloid (10). Basic chromosome numbers 4 (1 genus), 12 (2 genera) and 14 (5 genera).

Androcalymma, Apuleia, Baudouinia, Cassia, Ceratonia, Dansera, Dialium, Dicorynia, Distemonanthus, Duparquetia, Eligmocarpus, Kalappia, Koompassia, Labichea, Martiodendron, Mendoravia, Petalostylis, Storckielia, Uittienia, Zenia

IV. Detarieae (including Amherstieae) (81 genera)

Unarmed trees and shrubs. Leaves pinnate or (in 22 genera) bi-foliate, often (24) with twisted petiolules, stipules when present (and recorded) intrapetiolar, phyllotaxy spiral or distichous; abaxial epidermis nearly always (69) readily staining with safranin, often having hairs with expanded/embedded feet (25), not infrequently with epidermal crystals (17); nearly always having conspicuous phloem transfer cells (57/61), sometimes with unaligned mesophyll fibres and/or sclereids (12), often with secretory mesophyll cavities (gland-dotted). Wood sometimes with intercellular canals, sometimes storied (13/35).

Bracteoles nearly always present, small, imbricate and caducous to large, valvate and showy. Flowers sometimes distichous (17), usually (75) not pentamerous throughout calyx, corolla and androecium; calyx usually imbricate, sometimes very reduced; corolla usually somewhat to very zygomorphic, often with vestigial petals (32/65), sometimes absent; stamens 2-many, often (45) synandrous, anther dehiscence latrorse (11/11); pollen tectum striate (24), reticulate (18) or punctate (16); ovary usually excentric/adnate (51), but often central/free (29).

Seeds not endospermic (29/29); amyloid nearly always present (43/48). Cotyledons mainly of types 3–4.

Basic chromosome number usually 12 (21/27).

More genera in Africa (53) than in South America, and seemingly less well represented in Madagascar than are the Caesalpinieae (tribe I)

Subgroup 1 (22 genera)

Trees. The leaflets often alternate (12/18), often with a continuous marginal nerve (S/11); the mesophyll usually gland-dotted (16/18) with epithelium-lined secretory cavities (15/16). Wood usually with secretory canals (13/16). Bracteoles small, not valvate. Flowers mostly small, hypanthium often absent (11/20); corolla often (13 genera) absent. Pollen tectum punctate (8) or reticulate (5); ovary often sessile (10/20), usually central and completely free of adnation (16/20). Stamens usually 10 (19 genera), no staminodes. Fruits mostly indehiscent (17/22), less often a 2-valved pod (usually without twisting valves); seed sometimes (5/17) without amyloid. Basic chromosome numbers other than 12 in 5/10 genera.

1a (12 genera). Leaves bifoliolate (7 genera) or with few leaflets; epidermal crystals rare (2/10). Wood with scattered gum ducts. Flowers spirally disposed, calyx imbricate, corolla usually absent (9/12); stamen number sometimes other than 10 (5/12). Germination hypogeal in 2/6 genera.

Augouardia, Colophospermum, Gossweilerodendron, Guibourtia, Hardwickea, Hymenaea, Kingiodendron, Oxystigma, Peltogyne, Prioria, Stemonocoleus, Trachylobium

1b (10 genera). Leaves normally not bifoliolate, with few to (6 genera) many leaflets; epidermal crystals common (5/7). Wood with gum ducts in tangential lines. Flowers distichous and calyx subvalvate (in all 8 well known genera), corolla variously reduced but present in 7/10 genera; stamens nearly always 10. Germination epigeal (8/8).

Apaloxylon, Baikiaea, Bathiaea, Copaifera, Detarium, Gilletiodendron. Hylodendron, Sindora, Sindoropsis, Tessmannia

Subgroup 2 (59 genera)

Trees and (in about 20 genera) shrubs. The leaflets nearly always opposite (47/50), usually without a continuous marginal nerve (where recorded: 19/21), usually without mesophyll secretory cavities (gland-dots absent). Wood nearly always without secretory canals. Bracteoles large and enclosing the flowers (34) to small, valvate (24) or not, flowers often large and showy; hypanthium present (51/54); corolla early always present; staminodes often present (about 20 genera); pollen tectum usually striate (24) or reticulate (13), rarely punctate). Ovary nearly always stipitate (53/55), usually excentric/adnate (6/54); fruit usually a 2-valved pod (48/50), usually with twisting/enrolling valves (26/37), rarely indehiscent (6/50); seeds with amyloid. Basic chromosome number nearly always 12 (15/16).

2a (31 genera). Afzelia, Brachystegia, Brodriguesia, Cryptosepalum, Cynometra, Daniella, Endertia, Eperua, Eurypetalum, Gilbertiodendron, Goniorrachis, Hymenostegia, Intsia, Julbernardia, Lebruniodendron, Leonardoxa, Leucostegane, Loesenera, Macrolobium, Maniltoa, Neochevalierodendron, Oddoniodendron, Paramacrolobium, Plagiosiphon, Saraca, Schizoscyphus, Schotia, Scorodophloeus, Talbotiella, Tamarindus, Zenkerella

2b (6 genera). Aphanocalyx, Michelsonia, Microberlinia, Monopetalanthus, Pellegriniodendron, Tetraberlinia

2c (22 genera). Amherstia, Anthonotha, Berlinia, Brachycylix, Brownea, Browneopsis, Crudia, Dicymbe, Didelotia, Elizabetha, Englerodendron, Heterostemon, Humboldtia, Isoberlinia, Librevillea, Lysidice, Paloue, Paloveopsis, Phyllocarpus, Polystemonanthus, Pseudomacrolobium, Thylacanthus

V. Unclassified (2 genera)

Umtiza. Anatomical data required.

Poeppigea. Showing a number of similarities with Cassieae, including distichous phyllotaxy, leaves imparipinnate, leaflets opposite, with phloem transfer cells, adaxial epidermal walls straight, abaxial epidermis scarcely staining with safranin; corolla ‘pseudo-papilionaceous’; conspicuous disc present; no amyloid; but 10 fertile stamens and no staminodes, campanulate hypanthium, etc.