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Key to Fabaceae

Fabaceae

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1 Trees, shrubs, or woody vines; [subfamilies Caesalpinioideae, Mimosoideae, and Faboideae]
  2 Leaves 4-many-foliolate.
1 Herbs (including herbaceous vines).
        5 Leaves 4-many-foliolate.
        5 Leaves 0-3-foliolate ; [subfamily Faboideae].
                 9 Leaves 0, 1, or 3-foliolate.
                   10 Leaves trifoliolate (plants with some upper stem or lower stem leaves unifoliolate but with other trifoliolate leaves should be keyed here).
(c) Weise, Armin - C, permission granted to NCBG
                     11 Leaves palmately 3-foliolate (the petiolules of the 3 leaflets usually of similar length (if the apparent petiolule of the terminal leaflet is slightly longer, it does not have a joint between a rachis and the petiolule of the terminal leaflet)
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Key to Fabaceae, Key A: woody legumes with all leaves 1-, 2-, or 3-foliolate, or reduced to flattened phyllodia or phyllodial spines

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1 Stamens numerous; inflorescences of many flowers arranged in a closely packed sphere or cylinder; leaves replaced by phyllodes, these leathery in texture and often crescent-shaped; [Mimosoid clade]
1 Stamens 10 (or fewer); inflorescences various, the flowers larger and more diffuse; leaves 1-, 2-, or 3-foliolate, or reduced to phyllodial spines; [subfamily Faboideae or Cercidioideae]
  2 Leaves 1- or 2-foliolate and > 2 cm wide; trees, shrubs, or lianas.
    3 Seeds 1-2 (-4) per fruit; corolla pale yellow, pale pink, or white; longest petals 7-10 mm long; [subfamily Faboideae]
    3 Seeds > 5 per fruit; corolla purplish-pink, bright pink, or white; longest petals 10-100 mm long [subfamily Cercidioideae]
      4 Leaves with a rounded to apiculate apex; flowers strongly bilaterally symmetrical, “pseudopapilionoid”; petals 0.8-1.5 cm long; legumes 4-10 cm long; [natives and exotics, and widely cultivated]
      4 Leaves either unifoliolate with a deeply notched apex or 2-foliolate; flowers slightly bilaterally symmetrical; petals 1.5-8 (-10) cm long; legumes 7-30 cm long; [exotics, of FL peninsula].
        5 Shrub or tree; petals 3-8 (-10) cm long
  2 Leaves 3-foliolate, or reduced to phyllodial spines, or 1-foliolate (but then < 2 cm wide); shrubs or woody vines (rarely trees in Erythrina); [subfamily Faboideae].
          6 Woody vine (Pueraria, a robust herbaceous vine, is also keyed here as a failsafe).
             7 Leaves eglandular beneath; terminal leaflets 5-20 cm long.
               8 Terminal leaflet 1.5-2.5× as long as wide; corolla yellow; legume 4-6 cm wide; seeds 2-3 cm wide
               8 Terminal leaflet 0.8-1.3× as long as wide; legume 0.8-1.3 cm wide; seeds < 1 cm wide; corolla purplish or red.
          6 Shrub or tree.
                   10 Shrub with angled or flanged green twigs; leaves palmately trifoliolate, unifoliolate, or reduced to spine-tipped phyllodes; [introduced]; [tribe Genisteae].
                     11 Flowers red-purple; calyx 2-3 mm long; [tribe Galegeae]
                     11 Flowers bright yellow; calyx 3-15 mm long; [tribe Genisteae]
                       12 Leaves with normal lamina, either 1-foliolate or 3-foliolate; flowers in terminal racemes; calyx 3-6 mm long.
                          13 Leaves 3-foliolate lower on the stem, often 1-foliolate above; corolla 15-22 mm long
                          13 Leaves 1-foliolate throughout; corolla either 10-14 mm or 20-25 mm long
                   10 Shrub or tree with twigs various, but not conspicuously green or flanged; leaves pinnately trifoliolate or unifoliolate.
                                  17 Corolla 15-50 mm long, yellow or scarlet; legume with several seeds; leaflets lobed or not; [tribe Phaseoleae]
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Key to Fabaceae, Key B: woody legumes (trees, shrubs, or woody vines) with bipinnately compound leaves

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1 Leaves variously modified from strict 2-even-pinnateness, either with 1) a mixture (on a tree) of 1-even-pinnate and 2-even-pinnate leaves, and/or 2) the pinnae or leaflets often subopposite or fully alternate, and/or 3) with an odd number of pinnae per leaf (the tip of the rachis with a pair of lateral pinnae and a terminal pinna, but the leaflets of the pinnae still in opposite pairs), and/or 4) the basal pair of pinnae evolutionarily replaced by a single pair of leaflets larger than the other leaflets.
  2 Flowers small, inconspicuous, in catkin like-racemes or racemes of racemes; perianth greenish-white or greenish-yellow, with a cylindrical hypanthium to 10 mm long and shorter perianth lobes; flowers mostly unisexual; large trees; fruits woody and indehiscent at maturity, 1-5 cm wide[ collectively widespread in our region, but absent from s. FL and s. TX].
(c) Kinser, Abel - CC-BY-NC, permission granted to NCBG
    3 Leaves characteristically a mixture (on a tree) of 1-even-pinnate (mainly on spurs) and 2-even-pinnate (mainly on new growth), the pinnae and the leaflets strictly opposite or subopposite; leaflets 1.5-4 cm long, acute to rounded at the apex; trunks with simple, trident, or multiply branched thorns to 20 cm long (or unarmed)
    3 Leaves all 2-even-pinnate, the basalmost "pinna pair" usually replaced by a pair of leaflets larger than the others, the pinnae and the leaflets often 'straying' to subopposite or fully alternate arrangement (some pinnae appearing odd-pinnate); leaflets 3-6 cm long, acuminate at the apex; trunks unarmed
  2 Flowers either with conspicuous petals or aggregated into spikes or spherical heads with showy stamens; petals either (Caesalpinoids) yellow, orange, red, or (Mimosoids) the tubular perianth whorls less conspicuous than the stamens, these yellow to orange; flowers bisexual; small shrubs, shrubs, small or medium trees, or large trees (if large trees, then of tropical parts of our region); fruits papery or chartaceous (rarely woody), often < 2 cm wide; [collectively widespread, including of s. FL and s. TX].
      4 Leaves with pinnae and leaflets mostly subopposite or fully alternate; [exotic, s. FL]; [Mimosoid]
      4 Leaves with an odd number of pinnae per leaf (the tip of the rachis with a pair of lateral pinnae and a terminal pinna), but the leaflets in opposite pairs; [native or exotic, TX and OK]; [Caesalpinoid].
        5 Shrub or small tree, 5-50 dm tall; sepals ovate; leaflets not glandular, or with glands only along the leaflet margin
        5 Sprawling shrub, less than 6 dm tall; sepals linear; leaflets glandular punctate across the lower surface (these orange in life, drying black)
(c) Gabriel - CC-BY
1 Leaves strictly 2-even-pinnate (with pinna pairs borne opposite one another and no pinna terminal on the rachis, and with leaflets also born in opposite pairs).
          6 Pinna pairs 1-6 (-7) per leaf; leaflets 4-ca. 250 per leaf.
                 9 Shrub, small tree, or scrambling liana; branches armed with straight nodal spines or internodal catclaw prickles.
                   10 Branches armed with paired, straight, nodal spines, these simple or 3-branched; branches and larger stems green, photosynthetic; flowers caesalpinoid, 2-2.5 cm in diameter.
                   10 Branches armed with catclaw prickles scattered along internodes; branches and stems brown; flowers caesalpinoid or mimosoid.
                     11 Scrambling liana; flowers caesalpinoid, 1.5-2 cm across
                     11 Shrub; flowers mimosoid, aggregated into spherical inflorescences 9-15 mm in diameter
               8 Glands (stalked, columnar, or domed) 1 or more on petioles or rachises, on the petiole or at rachis nodes.
                                    18 Shrub or small tree; pinna pairs 2-5 (-6) per leaf; leaflet pairs 9-20 per pinna; fruit flat, straight.
                                       19 Spherical inflorescences 15-23 mm in diameter; stamens connate basally into a tube; fruits flat, about 1 cm wide, 2-4 mm thick
             7 Leaflets 10-60 mm long (at least the larger leaflets on a plant > 14 mm long).
                                           21 Pinna pairs 2-5 per leaf; branches armed with catclaw prickles scattered along internodes; flowers yellow to orange, caesalpinoid, each flower 0.7-2 cm across.
          6 Pinna pairs 4-25 per leaf (at least the larger leaves on a plant with > 6 pinna pairs); leaflets 150-3000 per leaf.
                                                              30 Branches armed with catclaw prickles scattered along internodes; shrub; flowers mimosoid, white, cream, or pink, aggregated into spherical heads 0.9-2 cm in diameter.
(c) Bradley, Keith
                                                                   32 Fruits 30-60 cm long, woody, persistent and indehiscent on the tree; flowers caesalpinoid, scarlet and yellow, 8-10 cm across; rachis with spheroidal projections at the nodes; petiole lacking glands
                                                                   32 Fruits < 20 cm long, papery, coriaceous, or woody; flowers mimosoid, white, cream, pink, or pale yellow, aggregated into spherical heads 1-6 cm in diameter; rachis lacking spheroidal projections; petiole bearing domed or saucer-shaped glands along the petiole or at the 1st pair of pinnae.
                                                                              37 Branches armed with paired nodal spines, these either narrow and needle-like or massive, hollow, and with an entrance hole; fruits turgid, straight or slightly curved
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Key to Fabaceae, Key C: woody legumes with evenly 1-pinnately compound leaves with 2 or more leaflets
[subfamilies Faboideae and Caesalpinioideae]

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1 Flowers with 5 petals, 2 fused to form the keel (papilionaceous); corolla rose, yellow, orange, red, pink, or white; [subfamily Faboideae].
  2 Shrubs; stamens 10, diadelphous (9 and 1).
    3 Leaflet pairs 10-25; [widespread]
    3 Leaflet pairs 4-6.
      4 Leaflets 10-25 mm long; corolla 15-20 mm long, yellow; [non-native cultivated and sparingly established]
      4 Leaflets 3-11 mm long; corolla 8-11 mm long, pink or white; [native, s. TX]
1 Flowers with 5 or 3 petals, all distinct (caesalpinaceous); corolla yellow, orange, red, or pink; [subfamily Detarioideae or Caesalpinioid clade].
        5 Large tree; sepals 4; petals 3; functional stamens 3; [subfamily Detarioideae]
        5 Shrub or small tree (< 5 m tall); sepals 5, petals 5, functional stamens 6-10; [Caesalpinoid clade].
          6 Trees; filaments of the 3 lower stamens curved; petiolar gland absent; [introduced in s. FL]
          6 Shrubs or trees; filaments of all stamens straight; petiolar and/or rachis gland(s) present or absent; [collectively more widespread].
             7 Leaflets 1.5-10.5 cm long, herbaceous; functional stamens 6-7 (10 in S. surattensis); [collectively more widespread, but especially FL and s. TX]
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Key to Fabaceae, Key D: woody legumes with oddly 1-pinnately compound leaves with 5 or more leaflets
[subfamilies

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1 Liana, climbing by twining; [tribe Millettieae]
  2 Inflorescence a stiff panicle; leaflets (5-) 7-9; ovary and fruit glabrous; leaves evergreen
  2 Inflorescence a pendent raceme; leaflets 7-19; ovary and fruit either glabrous or densely velvety-villous; leaves cold-deciduous
1 Shrubs and trees, lacking climbing adaptations.
    3 Leaflets glandular-punctate (not requiring magnification).
      4 Leaflets 4-10 cm long; leaves with 7-13 leaflets; large tree; flowers ca. 15 mm long, pink-purple; [tribe Milletieae]
      4 Leaflets 0.4-4 (-7) cm long; leaves with (7-) 9-31 leaflets; shrub or small tree; flowers 4-11 mm long, white, cream, violet, purple, or blue; [tribe Amorpheae].
        5 Corolla reduced to a single petal (the standard); flowers whitish, sky blue, dark blue, purple, or violet; [collectively widespread]
        5 Corolla of 5 petals; flowers white to cream, sometimes 'fading' to dark purple; [s. FL, TX].
          6 Flowers papilionoid, either cream, fading purplish, or bicolored white and purple; [s. FL, TX, OK]
          6 Flowers only slightly bilaterally symmetrical, white; [TX]
             7 Leaflets 3-9 per leaf; leaflets 2-15 (-20) cm long; small or large tree (to shrub in Dermatophyllum secundiflorum).
(c) Wang, Zihao - CC-BY
               8 Lateral leaflets all or mostly alternate along the rachis.
                 9 Leaflets (5-) 7-9 per leaf; flowers 18-25 mm long, white; [native, also planted; SC, GA, AL, MS, and LA northwards]
                 9 Leaflets 3-5 (-7) per leaf; flowers ca. 10 mm long, yellow-white or pinkish; [non-native; FL peninsula]
               8 Lateral leaflets strictly in opposite pairs.
                     11 Corollas 14-16 mm long, blue-purple; fruit turgid and cylindrical, but torulose-constricted between the scarlet seeds; [native; TX]
                     11 Corollas 7-11 mm long, cream to white; fruit flattened, not constricted between the tan to light brown seeds; [non-native]
                       12 Fruit woody, unwinged, with 1 very large (ca. 2 cm long) seed; stamens diadelphous
                       12 Fruit 2-9 cm long, membranaceous, with 4 broad, tan, ruffled wings and 1-6 black seeds; stamens monadelphous
             7 Leaflets (5-) 7-31 per leaf, at least the larger and better developed leaves on a plant with 11 or more leaflets; leaflets 0.4-12 cm long; shrub, small tree, or large tree.
                          13 Corollas 5-6 mm long, pink or purplish; fruits 15-35 mm long, 1-3 mm wide
                          13 Corollas 9-30 mm long, yellow, white, pink, or purplish; fruits 25-150 (-200) mm long, 5-35 mm wide.
                            14 Corollas ca. 10 mm long, pink or purplish; fruit a single-seeded, globose or broadly ellipsoid drupe, 2.5-4 cm long, 2-3 cm in diameter; leaflets 4-12 cm long; [s. FL]
                            14 Corollas 15-30 mm long, white, pink, purplish, or bright yellow or coppery; fruit a legume, seeds several; leaflets 2-6 cm long; [collectively widespread]
                              15 Corollas bright yellow or coppery; fruits about as thick as wide, either bladdery-inflated or moniliform (like beads on a string).
                                16 Fruits bladdery-inflated, 50-70 mm long, 20-30 mm in diameter; stamens diadelphous; [cultivated ornamental, rarely establishing]
                                16 Fruits moniliform (like beads on a string), 100-200 mm long, 7-8 mm in diameter at the seeds, 1-2 mm in diameter between the seeds; stamens free; [native of coastal peninsular FL and TX].
                              15 Corollas white, pink, or pink-purple; fruits flattened (wider than thick).
                                  17 Leaflets rounded, obtuse, or retuse (and also usually with a noticeable mucro) at the apex; calyx with lobes at its apex; branches sometimes armed with stipular (nodal) spines or internodal hispid hairs; [temperate, widespread in our region]
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Key to Fabaceae, Key E: herbaceous legumes with palmate leaves with 4 or more leaflets [subfamily Faboideae]

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1 Leaflets 4; corolla yellow; flowers enveloped by two closely appressed ciliate bracts; [tribe Dalbergieae]
1 Leaflets 5 or more (at least on the largest and best developed leaves); corolla blue, pink, or violet (except yellow in Lupinus luteus); flowers not enveloped by bracts.
  2 Leaflets and fruits not glandular-punctate; stamens monadelphous; [tribe Genisteae]
  2 Leaflets and fruits glandular-punctate; stamens diadelphous; [tribe Psoraleeae].
    3 Leaflets linear to very narrowly oblanceolate, 0.5-2.0 (-3.5) mm wide, > 10× as long as wide; [Coastal Plain]
    3 Leaflets broader, > 5 mm wide, 2-4.5× as long as wide; [collectively more widespread]
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Key to Fabaceae, Key F: herbaceous legumes with bipinnate leaves [subfamily Mimosoideae]

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1 Leaves with an odd number of pinnae (lateral pinnae paired, but an additional pinna present in a terminal position on the rachis); [Caesalpinoideae].
  2 Leaflets 0.9-1.6× as long as wide; terminal pinna with about 2× as many leaflet pairs (8-20) as the lateral pinnae (3-7)
  2 Leaflets 1.8-4× as long as wide; terminal pinna with about the same number of leaflet pairs as the lateral pinnae.
    3 Lower surfaces of leaflets densely glandular punctate, the glands orange when fresh and drying black
1 Leaves with an even number of pinnae (lateral pinnae paired).
(c) Sorrie, Bruce A. - CC-BY
      4 Coarse climbing or sprawling suffruticose herbs, the stems to 6 m long, and usually armed with retrorsely curved prickles; [Caesalpinoidaeae]
      4 Perennial herbs, less coarse; [Mimosoideae]
        5 Stamens > 10; [tribe Acacieae]
        5 Stamens 10 or fewer; [tribe Mimoseae].
          6 Petiole with 1-several glands; stems ascending to erect; flowers greenish-white
          6 Petiole without glands; stems prostrate to weakly arching; flowers pink-purple, yellow, or greenish-yellow.
             7 Flowers pink-purple; legume ribbed, the ribs with prickles
             7 Flowers yellow to greenish-yellow; legume not ribbed or prickly
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Key to Fabaceae, Key G: herbaceous legumes with once-pinnately, even-pinnately compound (or 'palmately' 2-foliolate) leaves with 2 or more leaflets
[subfamilies Faboideae and Caesalpinioideae]

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1 Flowers nearly regular; stamens 5-10, separate; [subfamily Caesalpinioideae, tribe Cassieae].
  2 Leaflets 5-25 pairs, each leaflet 0.5-1.5 cm long; stipules persistent, striate
  2 Leaflets (2-) 3-12 pairs, each leaflet 1.5-12 cm long; stipules caduceus, small, not striate
1 Flowers papilionoid; stamens diadelphous or monadelphous; [subfamily Faboideae].
    3 Tendrils lacking on all leaves; stamens monadelphous or diadelphous.
      4 Leaflets 2 per leaf; [tribe Aeschynomeneae]
      4 Leaflets 4-60 per leaf.
        5 Floating aquatic with stems swollen, inflated
        5 Terrestrial plants with stem not swollen
          6 Leaflets 20-60 per leaf; strong herbs (or woody) 1-4 m tall, simultaneously erect, > 1 m tall, and with stems usually > 5 mm in diameter
             7 Fruit a loment, with single-seeded segments separated by sutures; stamens monadelphous or diadelphous in 2 phalanges of 5; [tribe Aeschynomeneae]
          6 Leaflets 4-18 per leaf; weak or sprawling herbs to 1.5 m long, with weak stems usually < 5 mm in diameter (or if thicker, then < 1 m long; stamens monadelphous or diadelphous.
    3 Tendrils present in the terminal position on some or all leaves; stamens diadelphous; [tribe Fabeae].
                   10 Stipules smaller, typically much smaller than the leaflets.
                     11 Calyx lobes 1-2× as long as the calyx tube; [collectively widespread and common].
                       12 Style stout, flattened or folded, with a dense longitudinal band of hairs longitudinally arrayed along the inner side; stems ridged, angled, or longitudinally winged; leaflets 2-6 (-8) cm long; calyx 5-12 mm long
                       12 Style slender and hair-like, terete (round in ×-section), glabrous except for a ring of short hairs just below the stigma; stems ridged or angled, but not longitudinally winged; leaflets 0.5-4.5 cm long (except larger in a few waifs); calyx 2-8 mm long (except larger in a few waifs)
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Key to Fabaceae, Key H: herbaceous legumes with once-pinnately, odd-pinnately compound leaves with 5 or more leaflets
[subfamilies Faboideae and Caesalpinioideae]

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1 Lateral veins of each leaflet neatly straight and parallel to one another; [tribe Millettieae]
1 Lateral veins of each leaflet complicatedly and less regularly arrayed.
  2 Leaves (at least the largest and those with the most leaflets) with ≥ 13 leaflets.
    3 Ovaries (and later fruits) with dense, hooked prickles (looking like a miniature cocklebur, Xanthium); leaves and stems glandular-punctate with brown or black glands; stamens diadelphous (9 and 1); [rare waif in our area]; [tribe Galegeae]
    3 Ovaries (and later fruits) glabrous, glandular, or hairy; leaves and stems glabrous, variously hairy, but not glandular-punctate (except Dalea); stamens 5-10, monadelphous, diadelphous, or separate; [collectively widespread].
      4 Leaflets conspicuously dentate; [tribe Cicereae]
        5 Hairs dolabriform (with 2 branches parallel to the surface and pointing at 180° from each other).
          6 Petals reddish orange and/or with some pink or salmon; [tribe Indigofereae]
          6 Petals pink-purple to violet; [tribe Galegeae]
             7 Fruit a loment (jointed between each seed and splitting into single-seeded segments).
               8 Loments cylindrical, jointed but not noticeably constricted between the seeds; Inflorescence an umbel of (7-) 10-15 flowers; [tribe Loteae]
               8 Loments flattened, prominently constricted between the seeds; inflorescence a raceme or umbel of 2-8 flowers.
                 9 Corolla primarily white to pink; loments 1-2.5 cm long, not borne on a stipe; [tribe Coronilleae]
                 9 Corolla primarily yellow (sometimes also marked with pink or orange); loments 2-5 cm long, borne on a 1-20 mm long stipe (above the calyx); [tribe Dalbergieae]
             7 Fruit a legume (lacking joints between each seed, though sometimes the pod constricted).
  2 Leaves (the largest and those with the most leaflets) with < 11 leaflets.
                       12 Fruit a loment (constricted between each seed and splitting into single-seeded segments); petals primarily yellow (sometimes also marked with pink or orange); [of the se. Coastal Plain, from e. GA southwards and westwards]; [tribe Dalbergieae].
                       12 Fruit a legume (lacking constrictions between the seeds); petals variously colored; [collectively widespread].
                            14 Ovaries (and later fruits) with dense, hooked prickles; leaves and stems glandular-punctate with brown or black glands; stamens diadelphous (9 and 1); [rare waif in our area]; [tribe Galegeae]
                            14 Ovaries (and later fruits) glabrous, glandular, or hairy; leaves and stems glabrous, variously hairy, but not glandular-punctate (except Dalea); stamens 5-10, monadelphous, diadelphous, or separate; [collectively widespread].
                              15 Plants with basal rosettes, the basal and cauline leaves a mixture of simple and pinnately compound; [rare waif in our area]; [tribe Loteae]
                              15 Plants with primarily cauline leaves, all pinnately compound; [collectively widespread].
                                  17 Leaves with 5 leaflets, the 2 basal leaflets positioned like stipules at the base of the leaf (the leaf thus sessile); [tribe Loteae]
                                  17 Leaves with 5-9 (or fewer or more and then keyed elsewhere), the lower leaflets positioned above a definite petiole.
                                    18 Hairs dolabriform (with 2 branches parallel to the surface and pointing at 180° from each other; petals reddish orange and/or with some pink or salmon; flowers papilionaceous; stamens 10, diadelphous (9+1); leaflets often > 5 mm wide; legume 3+-seeded; flowers 5-12 mm long, in racemes; [tribe Indigofereae]
                                    18 Hairs basifixed; petals of various colors; flowers not papilionaceous, barely bilaterally symmetrical; stamens 5, monadelphous; leaflets 0.5-5 mm wide; legume 1-seeded; flowers very small, < 5.5 mm long, aggregated into tight spike; [tribe Amorpheae]
                                       19 Hairs dolabriform (with 2 branches parallel to the surface and pointing at 180° from each other; petals reddish orange and/or with some pink or salmon; [tribe Indigofereae]
                                         20 Flower usually solitary, resupinate (twisted at 180° so that the standard is below); standard 3.5-5 cm long
                                         20 Flowers few to many in racemes, normally oriented (with the standard above); standard < 2.5 cm long.
                                           21 Corolla purplish, maroon, brownish, or yellowish green; leaflets 4-9 cm long, on petioles 3-5 mm long; keel coiled
                                           21 Corolla either white with red striations or lavender; leaflets 2-5 cm long, on petioles 1-2 mm long; keel carinate, not coiled
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Key to Fabaceae, Key I: herbaceous legumes with all leaves unifoliolate or leaflets absent [subfamily Faboideae]

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1 Tendrils present on plant; leaves modified into tendrils (leaflike structures present clearly interpretable as stipules); [tribe Fabeae].
  2 Legume 4-7 mm wide; corolla 10-13 mm long
  2 Legume 12-20 mm wide; corolla 18-25 mm long
1 Tendrils absent; leaves or stipules present on plant and interpretable as leaves with 1 leaflet.
    3 Leaflet blades roundish, 0.6-1.5× as long as wide.
      4 Leaves with a well-developed petiole, > 0.5 cm long.
      4 Leaves sessile, subsessile, or perfoliate.
          6 Corolla bright or creamy yellow; stamens separate; leaves all 1-foliolate; leaflet blades perfoliate or sessile; [tribe Thermopsideae]
          6 Corolla violet to blue (drying pale); stamens diadelphous; leaves 1-foliolate and with some leaves 3-foliolate or 2-foliolate; leaflet blades cuneate, subsessile; [tribe Psoraleeae]
    3 Leaflet blades elongate, 1.5-15× as long as wide.
             7 Leaves basally disposed.
               8 Leaflet blades elliptic, widest near the midpoint of the blade; flowers pink, rose, or purplish; legume straight; [native of the Coastal Plain, se. NC south to s. FL, west to e. LA]; [tribe Genisteae]
               8 Leaflet blades oblanceolate, widest well past the midpoint of the blade; flowers yellow; legume coiled; [rare waif]; [tribe Loteae]
             7 Leaves all or primarily cauline.
                 9 Leaves long-petioled, the petiole > 2 cm long.
                   10 Petiole winged its entire length; leaflet blade 2-4× as long as wide, sagittate at the base; foliage not glandular; [tribe Phaseoleae]
                   10 Petiole not winged; leaflet blade 8-15× as long as wide, cuneate at the base; foliage glandular-punctate; [tribe Psoraleeae]
                 9 Leaves sessile, subsessile, or short-petiolate, the petiole < 1.5 cm long.
                     11 Stamens diadelphous; corolla purple, lavender, or cream, 5-15 mm long.
                       12 Corolla 11-15 mm long, purple; [se. and s. TX]; [tribe Diocleae]
                       12 Corolla 5-7 mm long, lavender or cream; [widespread in our area]
                          13 Flowers solitary in leaf axils; [tribe Loteae]
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Key to Fabaceae, Key J: herbaceous legumes with palmately trifoliolate leaves [subfamily Faboideae]

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1 Stamens separate, unfused; stipules (at least the lower on the stem) often persistent, foliaceous, not striate; corollas yellow, white, or purple-blue.
(c) Witsell, Theo - CC-BY-NC, permission granted to NCBG
  2 Legumes turgid, inflated; corolla white, cream, yellow, blue, or purple; [widespread in our area, especially Coastal Plain]
(c) Pogacnik, Shaun - CC-BY-NC, permission granted to NCBG
  2 Legumes laterally compressed; corolla yellow; [primarily montane, elsewhere as an escape from cultivation]
1 Stamens monadelphous or diadelphous; stipules either caducous or well-developed and persistent, and then separate or adnate to the petiole; corollas pink, blue, violet, yellow, or white.
          6 Calyx deeply 5-lobed; upright (rarely sprawling) annual herbs, mostly 8-20 dm tall
          6 Calyx with the upper 4 lobes connate; decumbent perennial herbs, the stems to 5 dm long
    3 Stamens diadelphous (9 and 1); corollas 3-16 mm long.
             7 Foliage punctate-glandular; corollas blue, violet, or white.
               8 Fruit beaked, the beak 3-7 mm long; corollas 7-12 mm long
             7 Foliage eglandular; corollas purple, pink, red, or white.
(c) Marcum, Paul
                 9 Lateral veins of each leaflet lateral veins neatly straight and parallel to one another; leaflets entire; [tribe Desmodieae]
(c) Cressler, Alan M.
                 9 Lateral veins of each leaflet complicatedly and irregularly arrayed; leaflets denticulate; [tribe Trifolieae]
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Key to Fabaceae, Key K: herbaceous legumes with pinnately trifoliolate leaves [subfamily Faboideae]

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1 Leaflets denticulate (sometimes inconspicuously so); [tribe Trifolieae].
  2 Inflorescences elongate racemes with an axis 5-15 cm long, the flowers well-spaced along the axis, the overall inflorescence much longer than its diameter
  2 Inflorescences umbellate or headlike clusters or short racemes with an axis < 2 cm long, the flowers closely clustered, the overall inflorescence little (if at all) longer than its diameter.
(c) Danielson, Erik
(c) Frumkin, Ron - CC-BY-NC, permission granted to NCBG
    3 Legumes spirally coiled or curved, often tuberculate or prickly; stems 4-angled towards the tip; leaves pinnately trifoliolate; calyx actinomorphic
    3 Legumes straight or nearly so, never tuberculate or prickly; stems terete or flattened (2-angled) towards the tip; leaves palmately 3-foliolate; calyx zygomorphic
1 Leaflets entire (and sometimes also with 1 or 2 broad lobes), or with scattered, irregular large teeth (Pachyrhizus erosus).
      4 Main stems erect or ascending, not trailing, twining, or otherwise vine-like.
        5 Flowers not papilionaceous (the wings and keel epistemonous, arising terminally or laterally from the stamen tube), barely bilaterally symmetrical; stamens 5, monadelphous; [tribe Amorpheae]
          6 Plants with separate leafy and flowering stems (the flowering stems naked or nearly so of leaves).
             7 Standard bright red, remaining folded, 30-50 mm long; leaves hastately lobed; fruit a torulose legume, 6-20 cm long, the seeds red; [tribe Phaseoleae]
             7 Standard white or pink, expanded, 4-8 mm long; leaves not hastate; fruit a flattened loment, < 5 cm long, the seeds drab; [tribe Desmodieae]
          6 Plants bearing leaves and flowers on the same stems.
               8 Leaves, stems, and/or calyces glandular-punctate.
                 9 Corollas pink or lavender/purplish; leaflets estipellate; fruit 1-seeded, indehiscent; [tribe Psoraleae]
                 9 Corollas yellow; leaflets stipellate; fruit 2-many-seeded, dehiscent; [tribe Phaseoleae, subtribe Cajaninae]
               8 Leaves, stems, and calyces lacking punctate glands.
                   10 Leaflet blades large, at least the largest terminal leaflets on a plant > 5 cm long.
                       12 Fruit a legume (not segmented into 1-seed dispersal units), hairy but the hairs not hooked; [plants cultivated as garden plants, rare as waifs]
                       12 Fruit a loment (separating into single-seeded segments), uncinulate (with hooked hairs, the fruits attaching to hairs or clothes as 'stick-tights'); [plants widespread, common]
                          13 Fruit a loment (separating into single-seeded segments), uncinulate (with hooked hairs, the fruits attaching to hairs or clothes as 'stick-tights'); [plants widespread, common]
                          13 Fruit a legume (not segmented into 1-seed dispersal units), hairy but the hairs not hooked; [plants cultivated as crops or garden plants, rare as waifs]
                            14 Keel of corolla coiled 1-3 turns; stipules conspicuous, persistent, striate; [bush green beans or lima beans]
                   10 Leaflet blades smaller, all on a plant < 5 cm long.
                                16 Fruit a loment (separating into single-seeded segments), uncinulate (with hooked hairs, the fruits attaching to hairs or clothes as 'stick-tights')
                                16 Fruit a several- to many-seeded legume, glabrous to hairy (but not uncinulate)
                                       19 Petioles fused most of length with amplexicaul stipules, the leaves thus appearing sessile or nearly so; corollas lemon to orangy yellow; flowers subsessile; fruit a loment of 2 segments, the terminal segment fertile, the lower segment either sterile or fertile
                                       19 Petioles free from stipules, leaves evidently petiolate; corollas white to pink; flowers pedicellate; fruit either 1-seeded, or a loment normally with 3+ segments
                                         20 Fruit 1-seeded; terminal leaflets 1-5 cm long, 1.2-8× as long as wide; stamens diadelphous (9 and 1)
      4 Main stems trailing, twining, creeping, or climbing or sprawling over other vegetation.
                                           21 Leaves, stems, and calyces lacking punctate glands; corollas yellow, pink, purplish, white, red, blue.
                                                      26 Fruit a loment (separating into single-seeded segments), uncinulate (with hooked hairs, the fruits attaching to hairs or clothes as 'stick-tights').
                                                                 31 Keel petal and the included style either strongly curved upwards 90-180 degrees, or even more extensively coiled (asymmetrically and spirally) in towards the flower center; stems slender to thicker, > 0.75 mm in diameter.
                                                                   32 Keel petal and the included style strongly curved upwards 90-180 degrees; corollas yellow or pink to lavender (or whitish).
                                                                     33 Corollas yellow (except pink in V. unguiculata); corolla keel symmetrical; [mainly outer Coastal Plain, introduced inland]
                                                                   32 Keel petal and the included style extensively coiled > 180 degrees (asymmetrically and spirally) in towards the flower center; corollas pink, purple, maroon, purple-black (or whitish).
                                                                       34 Peduncles short, the flowers scattered along a (sometimes branched) raceme axis, the raceme axis about as long as or longer than the peduncle; plants uncinulate pubescent (use 20× magnification, or touch the plant for the 'tacky' feel)
                                                                                    40 Keel petal and the included style either strongly curved upwards 90-180 degrees, or even more extensively coiled (asymmetrically and spirally) in towards the flower center; style or stigma pubescent.