MIMOSACEAE 577 



1. Albizzia Julibrl-ssin Durazz. An unarmed shrub or tree, reaching a height of 

 10 m. Bark scaly : leaves 2-4 dm. long, with 16-24 pinnae ; leaflets 50-70, the blades 

 oblong, inequilateral, acute : heads showy, pink, 4-6 cm. in diameter : corolla pink, 3-4 

 times longer than the calyx; lobes ovate: .stamens 3 3.5cm. long: pod broadly linear, 

 10-15 cm. long, acuminate at both ends, sometimes slightly constricted between the seeds. 



In sandy soil and woods, Virginia to Florida and Louisiana. Naturalized from Asia. Spring and 

 summer. 



5. LYSILOMA Benth. 



Unarmed shrubs or trees, with slender branches. Leaves alternate : blades pinnate : 

 each petiole often bearing a large gland : leaflets small and in many pairs, or large and in 

 few pairs. Flowers often polygamous, subtended by 3-lobed bractlets, in globose or cylin- 

 dric long-peduncled heads. Calyx campanulate, 5-lobed. Petals united into a 5-lobed 

 corolla. Stamens numerous : filaments united at the base. Ovary sessile or short-stalked : 

 style filiform. Ovules several, anatropous. Pods flat, linear or oblong, straight or falcate, 

 somewhat membranous. Seeds flattened, transverse. WILD TAMARIND. 



1. Lysiloma latisiliqua (L. ) Benth. An unarmed tree 5-16 m. tall, with wide- 

 spreading branches. Leaves 8-14 cm. long, with 4-8 pinnae ; leaflets 20-40, the blades 

 oblong or oblong-lanceolate, 8-11 mm. long, acute : heads about 1 cm. in diameter, white : 

 pods oblong, 8-15 cm. long, flat, undulate, each with a stipe 2-4 cm. long. 



In sandy soil, Florida Keys and the West Indies. Spring. 



6. ACACIA Adans. 



Shrubs or trees, or rarely herbs, usually armed. Leaves normal or sometimes reduced 

 to phyllodes : blades usually 2-pinnate, the pinnae numerous : leaflets often very numerous. 

 Flowers perfect or polygamous, in globose or cylindric spikes on axillary peduncles. Calyx 

 mostly campanulate, 4-5-lobed, or wanting. Petals 4-5, distinct or somewhat united. 

 Stamens numerous : filaments distinct, or the inner somewhat united at the base. Ovary 

 often stalked. Ovules 2-many. Pod flat, straight or curved, 2-valved or indehiscent. 



Leaflets of each pinna mostly more than 20. 



Pods over 15 mm. broad : the ultimate divisions of the leaf-rachis puberulent. 1. A. Berlandieri. 

 Pods less than 10 mm. broad : the ultimate divisions of the leaf-rachis glabrous 



or with few long hairs. 



Leaflets of each pinna 40-100, acute. 2. A. filicioides. 



Leaflets of each pinna 20-34, blunt. 3. A. cuspidata. 



Leaflets of each pinna mostly less than 20. 

 Flowers in head-like spikes. 



Pods less than 8 mm. broad, constricted between the seeds : leaflets less than 



1 mm. broad. 4. A. constricta. 



Pods over 15 mm. broad, not constricted between the seeds : leaflets over 2 



mm. broad. 5. A. Roemeriana. 



Flowers in elongated spikes or racemes. 

 Pods over 10 mm. broad. 



Flowers slender-pedicelled. 6. A. Wrightii. 



Flowers sessile or nearly so. 7. A. Greggii. 



Pods less than 10 mm. broad. 8. A. amentacca. 



1. Acacia Berlandieri Benth. A shrub, clothed with ashy pubescence, unarmed or 

 with few spines. Leaves 10-15 cm. long, with 10-18 pinnae ; leaflets 50-90, the blades 

 linear-oblong, 4-6 mm. long, oblique, prominently nerved, acute or acutish : spikes glo- 

 bose, slightly over 1 cm. thick : pods flat, linear, 10-15 cm. long, 18-20 mm. broad, usually 

 straight, obtuse or apiculate at the apex, each narrowed into a stipe at the base, the valves 

 velvety-tomentose, firm. 



On dry bluffs, southern Texas and Mexico. Spring. 



2. Acacia filicioides (Cav. ) Trelease. An unarmed shrub, with more or less densely 

 hirsute foliage, stems angled. Leaves 5-15 cm. long, with 8-30 pinnae or sometimes 

 fewer ; leaflets very numerous, the blades oblong or narrowly oblong, 4-5 mm. long : spikes 

 globose, about 1 cm. thick, on hirsute peduncles 1-2 cm. long : pods linear-oblong, 3-4 cm. 

 long, 6-9 mm. wide. [A filicina Willd.] 



On prairies and in sandy soil, Missouri and Kansas to Texas, Arizona and Mexico, also in Florida, 

 Spring, fruit ripe in summer. The wholly or partially glabrous form, sometimes occurring in Texas and 

 Florida, is A. filicioides Texensis (T. & G.) Small. 



3. Acacia cuspidata Schlecht. A low shrub, with sparingly pubescent foliage. 

 Leaves 2.5-7 cm. long, with 4-10 pinnae, the rachis and its divisions with few scattered 

 hairs ; leaflets 20-34, or rarely some of the pinnae with fewer, the blades thick, linear- 



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