Prosopis strombulifera
Fabaceae subfam. caesalpinioideae
Argentine screwbean
bipinnate, sometimes pinnate or tripinnate, 2-foliolate, or phyllodic.
caesalpinioid (noncaesalpinioid in Ceratonia) or mimosoid, bilateral or radial;
sepals distinct or connate;
petals (0 or)5(or 6), distinct or connate;
stamens (2–)5–250+, filaments distinct or connate, heteromorphic or some or all sometimes modified or staminodial, anthers basifixed or dorsifixed;
pollen in monads, tetrads, or polyads.
legumes, dehiscent or indehiscent, or loments (in Prosopis).
usually with an apical hilum, complex hilar valve absent, pleurogram on each face, open or closed;
embryo straight.
ruiziana Burkart (found in Argentina) has fruits to 2 cm longer than var. strombulifera;
plants produce only one or two fruits per inflorescence.
nectaries often present on petiole or rachis, sometimes stipular or bracteal.
lateral, free, or absent.
= 7, 8, 9, 11, 12, 13, 26, 28.
Prosopis strombulifera
Fabaceae subfam. caesalpinioideae
South America (Argentina, Chile) [Introduced, California]
nearly worldwide
Varieties 2 (1 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Genera 148, species ca. 4400 (38 genera, 174 species in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key to Genera of Subfamily Caesalpinioideae, Excluding Mimosoid Clade
2. Corollas absent; inflorescences often on older branches and trunk; leaves even-pinnate; legumes flat with thickened margins. | Ceratonia |
2. Corollas present; inflorescences not usually on older stems or trunk; leaves even- or odd-pinnate, often bipinnate; legumes flat or cylindric, without thickened margins. | → 3 |
3. Trees, often armed (with straight or branching thorns); inflorescences spicate clusters; flowers polygamous or dioecious; corollas not obvious; leaves clustered from spurs. | Gleditsia |
3. Trees, shrubs, or herbs, armed or unarmed; inflorescences not spicate clusters; flowers bisexual; corollas obvious; leaves clustered on spurs or not clustered. | → 4 |
4. Stamen filaments proximally villous, much longer than anthers; stems photosynthetic, yellowish green; leaves clustered, alternate from spurs, bipinnate but sometimes appearing pinnate; legumes constricted between seeds. | Parkinsonia |
4. Stamen filaments glabrous, usually nearly same length as anthers; stems not photosynthetic, brownish (except Senna armata); leaves not clustered on spurs, pinnate. | → 5 |
5. Trees; leaf petiole and rachis without glands; stamens 10, filaments of 3 abaxial stamens sigmoidally incurved, usually longer than anthers; legumes indehiscent, not corrugated over seeds; inflorescences usually terminal. | Cassia |
5. Herbs, shrubs, or trees; leaf petiole and rachis with or without glands; stamens (2 or)3–10, all filaments straight; legumes dehiscent or indehiscent, often corrugated over seeds; inflorescences terminal or axillary. | → 6 |
6. Bracteoles absent; petals subequal; stamens 6–10, usually dwindling from one side to the other; legumes either indehiscent or tardily dehiscent through 1 or both sutures, if the latter then not coiling, or valves breaking into 1-seeded joints; stipules inconspicuous; flowers in axillary racemes, sometimes aggregated into compound racemes; root nodules absent. | Senna |
6. Bracteoles present; petals unequal; stamens (2 or)3–10, radially symmetric or bilateral, equal or irregularly unequal; legumes elastically dehiscent, valves coiling; stipules conspicuous, striate, often persistent; flowers in reduced few-flowered axillary racemes; root nodules present. | Chamaecrista |
1. Leaves bipinnate (sometimes also pinnate, rarely unifoliolate). | → 7 |
7. Trees; flowers usually unisexual, appearing apetalous, polygamous or dioecious; petals and sepals small and similar, greenish yellow; legumes usually pulpy between seeds. | → 8 |
8. Trees unarmed; leaves bipinnate, leaflet blade margins entire; inflorescences terminal, racemes or panicles; legumes thick, turgid, woody; seeds 2–5, subglobose. | Gymnocladus |
8. Trees often armed with simple or branched thorns (cultivars sometimes unarmed); leaves bipinnate in terminal growth, pinnate from spur shoots, leaflet blade margins often crenulate; inflorescences axillary, spicate racemes; legumes usually thin, flat, flexible; seeds 1–25(–30), compressed to subterete. | Gleditsia |
7. Trees, shrubs, herbs, or vines; flowers bisexual, obviously petalous; petals and sepals easily differentiated; legumes not pulpy between seeds. | → 9 |
9. Trees, 8–35 m, unarmed. | → 10 |
10. Corollas yellow, less than 25 mm diam., petals not clawed; calyx imbricate; stigma peltate, broad; stipules 1 mm, triangular, entire; legumes 4–12 cm, margins winged, indehiscent; seeds 1–4. | Peltophorum |
10. Corollas scarlet and yellow, 80–100 mm diam., petals clawed; calyx valvate; stigma capitate; stipules 5–15 mm, pinnate; legumes 30–60 cm, margins not winged, dehiscent; seeds 20–40. | Delonix |
9. Herbs, shrubs, subshrubs, or small trees to 6 m, armed or unarmed. | → 11 |
11. Leaves odd-bipinnate. | → 12 |
12. Leaflet blades not glandular-punctate (inflorescences often conspicuously glandular-pubescent); calyx persistent in fruit. | Hoffmannseggia |
12. Leaflet blades glandular-punctate; calyx deciduous or persistent in fruit. | → 13 |
13. Shrubs, trees, or perennial herbs; stipules ovate, lanceolate-ovate to deltate or suborbiculate, usually early deciduous, persistent, or subpersistent; sepals ovate-lanceolate to orbiculate, persistent in fruit; androecium and gynoecium free, not cupped in lower sepal; legumes lanceolate-oblong; leaflet blades eglandular or with conspicuous black, sessile glands along margin, these sometimes sunken in sinuses of crenulated margin. | Erythrostemon |
13. Shrubs, subshrubs, or perennial herbs; stipules filiform or linear to lanceolate, persistent or tardily deciduous; sepals linear, deciduous in fruit; androecium and gynoecium cupped in the lower sepal; legumes oblong, oblong-lanceoloid, lunate, or ovate; leaflet blades with multiple orange, glandular dots on abaxial surfaces (drying black). | Pomaria |
11. Leaves even-bipinnate. | → 14 |
14. Legumes covered with prickles on faces; seeds ovoid or globose to subglobose, 15–25 mm wide; flowers functionally unisexual, segregated on separate male and female racemes. | Guilandina |
14. Legumes not covered with prickles; seeds ovoid or ellipsoid, 4–10 mm wide; flowers bisexual. | → 15 |
15. Legumes indehiscent, compressed or subterete, valves not twisting. | → 16 |
16. Branches brown or gray-brown; legumes oblong, compressed, ± fleshy, leathery; calyx irregular, abaxialmost sepal covering others in bud; petals yellow, banner with red medial markings. | Tara |
16. Branches green or yellowish green; legumes oblong to linear, compressed or subterete, sometimes torulose; calyx nearly radially symmetric, valvate, sepal lobes nearly distinct; petals all yellow, banner without red markings. | Parkinsonia |
15. Legumes dehiscent, valves twisting, laterally-compressed. | → 17 |
17. Corollas yellow to orange or red; petals glabrous. | Caesalpinia |
17. Corollas consistently yellow, banner sometimes with red marks; petals pubescent. | Denisophytum |
Key to Genera of Subfamily Caesalpinioideae, Mimosoid Clade
1. Stamens 5–10. | → 2 |
2. Shrubs or trees, usually armed with nodal spines or thorns; fruits legumes or loments, indehiscent or dehiscent, elongate, turgid, and often irregularly moniliform, or coiled springlike, rarely irregularly twisted or contorted. | → 3 |
3. Pinnae 1 or 2 pairs; fruits loments, straight or spirally coiled, seeds distinct nearly to base; inflorescences axillary, spikes or globose heads, 40–100+-flowered, corollas yellow, cream-yellow, purple-brown, greenish white, or yellow-green, all bisexual; sc, sw United States. | Prosopis |
3. Pinnae 7–15 pairs; fruits legumes, contorted or coiling at maturity; inflorescences axillary, pendent spikes, 50–200-flowered, corollas pale green, distally bisexual with bright yellow anthers, and proximally sterile with purple or white staminodes; introduced, Florida. | Dichrostachys |
2. Herbs, shrubs, or trees, unarmed, or with internodal prickles which are generally curved and flattened; fruits legumes, dehiscent or segmenting. | → 4 |
4. Perennial herbs, unarmed, terrestrial or floating-aquatic; stems ascending, decumbent, prostrate, prostrate-ascending, or floating; corollas yellow-green to white; distal flowers often bisexual, proximal flowers sterile with petaloid staminodes (monomorphic in N. lutea). | Neptunia |
4. Trees, shrubs, subshrubs, or perennial herbs, usually unarmed, sometimes armed, terrestrial; stems erect, ascending, decumbent, prostrate, or sprawling; corollas white, cream, yellow, greenish white, pink, purple, or purple-pink; flowers usually bisexual. | → 5 |
5. Trees, 5–15(–40) m, unarmed; leaflet blades 15–45 mm, alternate; inflorescences in terminal panicles or axillary spikelike racemes; corollas white to cream; legumes straight to falcate or contorted, swollen around seeds, valves twisting; seeds glossy red, flattened; stipitate anther glands present; introduced, Florida. | Adenanthera |
5. Trees, shrubs, subshrubs, or herbs, 0.1–3 m, unarmed or armed; leaflet blades 1.5–26(–30) mm, opposite; inflorescences in heads, spikes, or racemes; corollas white, greenish white, pale green, yellow, or pink to purple; legumes straight or curved, not swollen around seeds; seeds not glossy red; stipitate anther glands absent. | → 6 |
6. Petiole nectar glands absent; legumes often craspedial, segmented into 1-seeded portions separating from persistent sutures (replum), sometimes unsegmented; plants armed with recurved or straight prickles or unarmed; corollas white or pink to purple. | Mimosa |
6. Petiole nectar gland present (sometimes minute); legumes not craspedial; plants without prickles; corollas white, greenish white, or yellow. | → 7 |
7. Shrubs or trees, 2–18(–20) m; stems erect; stipules ovate, inconspicuous; inflorescences globose heads; corollas yellow, white, or greenish white; legumes shortly stipitate, linear or oblong, compressed or flat, valves sometimes curling. | Leucaena |
7. Herbs or shrubs, to 3 m; stems erect to prostrate or decumbent; stipules subulate, small but evident; inflorescences condensed heads or spikes; corollas pale green or white; legumes sessile, linear or falcate, subterete to flattened, splitting along margins at maturity. | Desmanthus |
1. Stamens 14–250. | → 8 |
8. Filaments distinct (except rarely connate basally in Acacia); leaves bipinnate or simple phyllodia. | → 9 |
9. Leaves simple phyllodia or bipinnate; stipular spines usually absent (except A. paradoxa); seeds usually with pulpy aril forming a cap or encircling seed. | Acacia |
9. Leaves bipinnate; stipular spines present or absent; seeds usually without pulpy aril (except sometimes in Vachellia). | → 10 |
10. Stipular spines present, sometimes enlarged and inhabited by ants; ovaries sessile or subsessile; seeds sometimes surrounded by pulp. | Vachellia |
10. Stipular spines absent; ovaries stipitate; seeds not surrounded by pulp. | → 11 |
11. Petiolar glands absent; prickles absent; inflorescences usually in globose heads; corollas greenish white, drying to pink-rose; stamens 175–250, creamy white, anther glands absent. | Acaciella |
11. Petiolar glands usually present; prickles present or absent; inflorescences spikes or heads; corollas white to creamy white or yellow; stamens 35–160, white, small anther glands sometimes present. | → 12 |
12. Prickles usually present; stipules caducous; inflorescences terminal or axillary, heads or spikes, usually in pseudoracemes or pseudopanicles; ovaries stipitate or sessile, with nectariferous disc at base; stamens creamy or yellow, fading to reddish brown. | Senegalia |
12. Prickles absent; stipules persistent; inflorescences axillary, cylindrical spikes; ovaries short-stipitate, nectariferous disc absent; stamens white. | Mariosousa |
8. Filaments fused into a tube, monadelphous; leaves bipinnate. | → 13 |
13. Legumes usually dehiscent into 2 valves, sometimes craspedial; nectary glands present or absent. | → 14 |
14. Trees, shrubs, or herbs, unarmed; stipular spines absent. | → 15 |
15. Petiole nectary glands present; inflorescences axillary spikes or racemes; legumes straight, flat, membranous, with 2 prominent suture ribs surrounding periphery and detaching after dehiscence (craspedial); exocarp dark purple to blackish, exfoliating. | Lysiloma |
15. Petiole nectary glands absent; inflorescences axillary or terminal heads sometimes in short pseudopanicles; legumes straight or slightly curved, dehiscent longitudinally along sutures, valves strongly recurving; exocarp dark brown to green, not exfoliating. | → 16 |
16. Heads globose; corollas greenish white; stamens 30–60; legumes dehiscing elastically from distal end to proximal end. | Zapoteca |
16. Heads ± hemispheric or obconic; corollas reddish or whitish; stamens (14–)19–28; legumes dehiscing longitudinally along sutures but not elastically. | Calliandra |
14. Shrubs or trees, usually armed; stipular spines present. | → 17 |
17. Legumes recurved to coiled into a circle; seeds with aril; petiolar nectary gland between lowest pair of pinnae; leaflet blade venation pinnate. | Pithecellobium |
17. Legumes straight; seeds without an aril; petiolar nectary gland borne between distalmost pair(s) of pinnae; leaflet blade venation brochidodromous. | Havardia |
13. Legumes indehiscent, dehiscent, or late dehiscent; nectary glands present. | → 18 |
18. Legumes falcate or forming a nearly complete flattened spiral, valves woody, dull light brown to maroon or blackish; inflorescences racemes, pseudoracemes, or heads (fascicles) or flowers solitary. | → 19 |
19. Pinnae 2 or 3 pairs; inflorescences pseudoracemes from short shoots; legumes falcate, light brown to maroon. | Ebenopsis |
19. Pinnae 4–10(–15) pairs; inflorescences heads; legumes forming a nearly complete flattened spiral, blackish. | Enterolobium |
18. Legumes straight or slight curved, valves papery, membranous, leathery, or if woody, glossy red-brown; inflorescences umbels, spikes, racemes, or heads. | → 20 |
20. Legumes turgid, fleshy, pulpy, margins thickened, septate between seeds; flowers dimorphic, peripheral flowers smaller than central; introduced, Florida. | Samanea |
20. Legumes flat, not fleshy or pulpy, not septate between seeds; flowers sometimes dimorphic; Florida (Lysiloma), California (Paraserianthes), or widespread (Albizia). | → 21 |
21. Legumes with prominent sutural ribs surrounding periphery and persistent, not separating from the valves (or tardily), seeds released through decay of valves; Florida. | Lysiloma |
21. Legumes without prominent peripheral ribs, raised over seeds; widespread. | → 22 |
22. Pinnae 20–30+ pairs; inflorescences axillary, racemes, flowers homomorphic, corollas greenish; stamens ± 90, equaling petals, greenish to lemon yellow; legumes indehiscent or late-dehiscent; introduced, California. | Paraserianthes |
22. Pinnae (1 or)2–12 pairs; inflorescences axillary or terminal, heads or corymbs; flowers dimorphic, corollas whitish or pink to yellow-green; stamens 20–70, usually long-exserted, pink or white; legumes dehiscent or late-dehiscent; widespread. | Albizia |
CA
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