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1 Leaves palmately (1-) 3-7-foliolate; plant a caulescent or acaulescent herb; corolla blue, lavender, or purple to cream or white; [collectively widespread]. | |
2 Plants acaulescent or nearly so, the aboveground stem 0-2 cm long; leaves (3-) 5-7-foliolate; corollas 11-18 mm long. | |
3 Upper calyx lobes ca. 1 mm long, much shorter than the calyx tube; leaflets 5-7; [calcareous glades of the Interior (nw. GA, TN, n. AL)] | |
3 Upper calyx lobes 5-8 mm long, longer than or about the same length as the calyx tube; leaflets (3-) 5; [sw. AR and w. LA westward]. | |
4 Peduncles 1.0-3.5 cm long, < 1/2 as long as the subtending petiole; [wc. OK and nc. TX westwards and northwestwards] | |
4 Peduncles (1.7-) 4-14 cm long, > 1/2 as long as the subtending petiole. | |
5 Peduncles and petioles spreading pilose; leaflets 1.7-3.0× as long as wide, mostly 10-30 mm wide; [sw. AR and w. LA west through e. OK and e. TX] | |
2 Plants caulescent, 3-10 dm tall; leaves (1-) 3-7-foliolate; corollas 5-25 mm long. | |
8 Corollas 12-18 mm long; calyx 8-10 mm (when in flower), enlarging to as much as 15 mm in fruit | |
8 Corollas 9-11 mm long; calyx 4.5-5.5 mm long (when in flower), only slightly enlarging in fruit | |
10 Leaflets 1.0-1.8× as long as wide; petiolules 5-9 mm long; calyx ca. 7 mm long (when in flower), elongating to ca. 10 mm (in fruit); [se. VA south to c. peninsular FL, west to AL] | |
10 Leaflets 2.0-4.0× as long as wide; petiolules 1.5-3 mm long; calyx 11-16 mm long; [SC and GA (P. piedmontanum) or OK and TX (P. reverchonii)]. | |
11 Inflorescence nodes (4-) 6-13 (-15), each with (1-) 3 (-4) flowers; [lower Piedmont of SC and GA] | |
11 Inflorescence nodes 2-3, each with 1-3 flowers; [Cross Timbers and Prairies region of sc. OK and nc. TX] | |
13 Leaflets 2-4.5× as long as wide; herbs silvery sericeous; pedicels 0.5-1 mm long; [nc. OK westwards] | |
12 Inflorescences not interrupted; plant strict (unbranched) or moderately branched; corollas 14-25 mm long; leaflets 2-5 (-6)× as long as wide. | |
14 Plants eglandular (lacking sessile glands on stems, foliage, etc.); stems 0.3-5 dm tall; [e. OK, n. AR, and s. MO northward and westward] | |
14 Plants glandular; [e. OK and e. TX westward]. | |
15 Larger stipules 2.5-7 mm wide. | |
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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. | |
3 Legumes straight or nearly so, never tuberculate or prickly; stems terete or flattened (2-angled) towards the tip | |
1 Leaflets entire (and sometimes also with 1 or 2 broad lobes), or with scattered, irregular large teeth (Pachyrhizus erosus). | |
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). | |
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 legume (not segmented into 1-seed dispersal units), hairy but the hairs not hooked; [plants cultivated as crops or garden plants, rare as waifs] | |
10 Leaflet blades smaller, all on a plant < 5 cm long. | |
15 Stipels absent on the petiolules of mature leaflets. | |
17 Fruits indehiscent: either 1-seeded, or a loment with 2 or more one-seeded (indehiscent) segments. | |
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 a loment, with 1-3 segments; terminal leaflets 3-10 cm long, 1-1.5× as long as wide; stamens monadelphous | |
20 Fruit 1-seeded; terminal leaflets 1-5 cm long, 1.2-8× as long as wide; stamens diadelphous (9 and 1) | |
21 Leaves, stems, and calyces lacking punctate glands; corollas yellow, pink, purplish, white, red, blue. | |
22 Leaflet blades smaller, all on a plant < 5 cm long. | |
23 Stipels absent on the petiolules of mature leaflets. | |
26 Fruit a loment (separating into single-seeded segments), uncinulate (with hooked hairs, the fruits attaching to hairs or clothes as 'stick-tights'). | |
28 Flowers resupinate (the pedicel twisted 180 degrees), the banner 2.5-5.5 cm long and positioned lowermost. | |
22 Leaflet blades large, at least the largest terminal leaflets on a plant > 5 cm long. | |
35 Stipels present, persistent (minute in Amphicarpaea); stamens diadelphous (9 and 1) or monadelphous (Pueraria). | |
36 Stamens monadelphous; robust herbaceous vine with stems to 30 m long; flowers purple, when fresh smelling like artificial grape flavoring. | |
36 Stamens diadelphous (9 and 1); herbaceous vines with stems usually < 5 m long; flowers various in color, not 'grapy' in odor. | |
37 Flowers not resupinate, the banner (standard) uppermost; banner (standard) < 25 mm long, or if up to 30 mm then not much longer than the other petals. | |
42 Leaflets with entire margins (sometimes with 1-2 rounded lobes); roots slender | |
43 Corolla < 2 cm long; fruits constricted or not; fruits glabrous or hairy, the hairs not stinging. | |
47 Flowers arrayed differently; upper calyx lobes separate. | |