Phaseolus
bean, wild bean
usually prostrate to climbing, rarely erect, striate, often lignescent, pubescent, covered with oblique to appressed, retrorse hairs, interspersed with finely uncinate, minutely hooked hairs.
alternate, odd-pinnate;
stipules and stipels present (terminal ones ascending, those of lateral leaflets spreading), at times covered with glandular hairs, these nectariferous;
petiole present, petiole and rachis canaliculate;
leaflets 3, blade margins entire, surfaces glabrous or pubescent.
(1–)3–60+-flowered, terminal or axillary, usually pseudoracemes, rarely also with basal and lateral branches (compound racemes), (1 or)4–60 floral nodes, not swollen, often biflorous;
primary bracts present, usually persistent, secondary bracts at base of pedicels;
bracteoles minute or equal to calyx tube;
bracts and bracteoles often nectariferous as stipules.
equal to or longer than calyx tube, arcuate or reflexed in fruit.
papilionaceous;
calyx campanulate or campanulate-tubular, lobes 5, usually shorter than tube, adaxial usually ± connate throughout;
corolla pink, purple, red, violet, or white;
banner glabrous abaxially, often hairy adaxially, slightly to strongly thickened at point of reflexion, often with two intramarginal thickenings;
wings longer than other petals;
keel beaked, apex 1.5–2 laterally and tightly coiled, coils 1.5–5.5 mm diam.;
stamens 10, diadelphous, vexillary stamen dilated or with globose to bladelike appendage basally;
anthers dorsifixed alternating with basifixed;
pollen tricolporate to triporate, often with pseudocolpi;
ovary with nectary disc at base, linear;
stigma introrse, laterally or extrorsely placed because of stylar rotation, apical or extrorse.
legumes, sessile or stipitate, usually falcate, sometimes straight, linear or oblong, short-beaked, usually elastically dehiscent, membranous, papery, or leathery, compressed or expanding over seeds, glabrous or pubescent.
1–20, oblong, quadrate, suborbicular, or reniform;
epihilum white.
, annual or perennial, unarmed;
roots tuberous or elongated (non-tuberous) taproots or fibrous.
= 10, 11.
Phaseolus
Species 70 (12 in the flora).
Phaseolus species share an indument of uncinate hairs, inflorescences with non-swollen floral nodes, bracts that are usually persistent, pedicels that are longer than the calyx tubes, and floral keel petals that are distally coiled laterally. The pseudoracemes or compound racemes have two (or three) flowers per node (this with a primary bract), and each flower is subtended by a secondary bract and two bracteoles covering partially or completely the sides of the calyx, at the apex of each pedicel. Some Phaseolus species develop reduced lateral inflorescences (G. Prenner 2013). The latter are referred to as panicles by G. F. Freytag and D. G. Debouck (2002). The seedlings have hypogeal or epigeal germination; in the flora area all species have hypogeal seedlings, except P. acutifolius and P. filiformis. A phylogenetic classification of the different groups of species in Phaseolus has been proposed (A. Delgado-Salinas et al. 2006).
Phaseolus has five cultivated species, and at least two (P. lunatus Linnaeus and P. vulgaris Linnaeus) have numerous cultivars and are important sources of food worldwide. Four species (P. acutifolius, P. coccineus Linnaeus, P. lunatus, and P. vulgaris) are grown in the United States and have been reported to escape (D. Isely 1998).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Inflorescences often with basal floral branches; c, e North America (including e Texas). | → 2 |
2. Leaflet blades leathery, bases obtuse or broadly rounded and lobed, apices obtuse to acute, venation reticulate; inflorescences with flowers clustered apically, rarely with basal floral branches; legumes 35–55 × 8–10 mm. | P. sinuatus |
2. Leaflet blades membranous to leathery or slightly papery, bases rounded to depressed-ovate or truncate, apices usually acute to acuminate, rarely obtuse, venation not reticulate; inflorescences usually with basal floral branches; legumes (30–)45–78(–86) × 7.5–13 mm. | → 3 |
3. Leaflet blades ovate to rhombic-ovate, not lobed basally; corollas 10–12 mm; legumes (30–)45–78(–86) × 7.5–13 mm. | P. polystachios |
3. Leaflet blades ovate-lanceolate, distinctly 3-lobed, with rounded or quadrate lobes basally; corollas 13 mm; legumes 53–60 × 8–10 mm. | P. smilacifolius |
1. Inflorescences without basal floral branches; sw United States. | → 4 |
4. Inflorescences with (1 or)2–6 biflorous (or usually 1-flowered in P. parvulus) nodes; roots fibrous, tuberous, or slender taproots. | → 5 |
5. Roots fibrous or slender taproots; bracteoles linear to lanceolate or oblong-ovate to narrowly triangular, 0.6–1.8 mm; legumes linear-falcate, 23–70 × 4–9 mm; seeds 4–10. | → 6 |
6. Leaflet blades ovate to widely ovate or linear to lanceolate, often weakly to conspicuously lobed on one or both sides basally, apices acute to attenuate, bases rounded or truncate to cuneate, 2.5–11.5 × 0.3–5 cm; legumes 32–70 × 5–9 mm; seeds 5–10, oblong, 3–6 × 2.5–5.5 mm, smooth to slightly rugose. | P. acutifolius |
6. Leaflet blades ovate in outline, not lobed or shallowly to deeply lobed basally (lobes quadrate-obtuse to oblong-attenuate), apices obtuse to acute, bases broadly cuneate to truncate, 1–5 × 1–4.5 cm; legumes 23–35 × 4–5 mm; seeds 4–7, usually oblong to quadrate, rarely reniform, 2–4.3 × 2.3–4 mm, rugose. | P. filiformis |
5. Roots tuberous; bracteoles ovate to lanceolate, oblong, or obsolete, 0.1–0.5 or 1–1.5 mm; legumes linear-falcate or linear-straight to slightly falcate, 23–45 × 3–8 mm; seeds 3 or 4, or 8–11. | → 7 |
7. Taproots elongate; stems climbing or trailing, to 150 cm; leaflet blades linear, narrowly oblong to lanceolate, or narrowly trullate; calyces campanulate; corollas 12 mm; bracteoles 1–1.5 mm; legumes linear-falcate, 23–30 × 4–8 mm; seeds 3 or 4, oblong, 3.5–5 × 3–4 mm, rugose. | P. angustissimus |
7. Taproots oblong or spherical; stems erect, trailing, or twining, 5–50 cm; leaflet blades usually linear to lanceolate, sometimes narrowly trullate; calyces campanulate-tubular; corollas 15–25 mm; bracteoles 0.1–0.5 mm; legumes linear-straight to slightly falcate, 35–45 × 3–4 mm; seeds 8–11, oblong or reniform, 2–3.7 × 1.7–2.6 mm, smooth.. | P. parvulus |
4. Inflorescences with (3–)6–25 biflorous (sometimes 3-flowered in P. texensis) nodes; roots tuberous or taproots (often large and thick). | → 8 |
8. Leaflet blades leathery, apices usually obtuse to rounded, retuse to emarginate, strongly apiculate; stipules ovate to lanceolate, 5–10 × 1–2.5 mm; primary bracts (2–)3–6.5(–8) mm; legumes sessile, oblong, somewhat curved, valves leathery, weakly dehiscent, 30–74 × 12–17 mm. | P. maculatus |
8. Leaflet blades membranous to firm, papery, or leathery, apices acute, long-acuminate, apiculate, or obtuse, sometimes apiculate; stipules oblong or triangular, lanceolate, widely ovate, or orbiculate, 1.5–7 × 0.5–4 mm; primary bracts 1–5(–10) mm; legumes sessile or stipitate, oblong- or linear-falcate, or oblong and slightly falcate, valves thin, papery, or leathery, elastically dehiscent, (10–)30–53 × 3–11(–15) mm. | → 9 |
9. Leaflet blades leathery, not lobed, apices acute; petioles shorter than terminal leaflet (often only pulvinus); legumes stipitate, stipe to 5.5 mm. | P. ritensis |
9. Leaflet blades membranous to slightly papery or firm, faintly to deeply 3-lobed (lobes often dissected), apices acute, sometimes apiculate; petioles often equaling or longer than terminal leaflet; legumes sessile. | → 10 |
10. Leaflet blades faintly or deeply 3-lobed, dissected. | P. scabrellus |
10. Leaflet blades ovate to slightly lobed basally, not dissected. | → 11 |
11. Stipules triangular to widely ovate or orbiculate, 4–7 mm; banners 4–8 mm; legumes sparsely covered with long, incumbent and hooked hairs; Arizona. | P. leptostachyus |
11. Stipules lanceolate, 1.5–3 mm; banners 12 mm; legumes strigose; Texas. | P. texensis |
CA
WildflowerSearch
iNaturalist
USDA Plants Database
