LEGUMINOS^: 559 



and armed with usually flattened simple or short-branched straight or falcate 

 sharp rigid spines 3'-5' long, about ' broad at the base, and dark red-brown and lus- 

 trous. Bark ^' ^' thick, smooth, dull gray or reddish brown, and divided by shallow 

 fissures into small plate-like scales. Wood heavy, very hard and strong, coarse- 



grained, rich bright brown tinged with red, with thick light clear yellow sapwood of 

 about 40 layers of annual growth. 



Distribution. South Carolina to Matanzas Inlet, Florida, through the coast 

 region of the Gulf states to the valley of the Brazos River, Texas, and northward 

 through western Louisiana and southern Arkansas to middle Kentucky and Ten- 

 nessee, the bottoms of the Mississippi at La Pointe, Saint Charles County, Missouri, 

 and western and southern Illinois and Indiana; rare east of the Mississippi River 

 and only in deep river swamps; very abundant and of its largest size westward on 

 rich bottom-lands; and in Louisiana and Arkansas often occupying extensive tracts 

 submerged during a considerable part of the year. 



9. PARKINSONIA, L. 



Trees or shrubs, with smooth thin bark, and terete branches often armed with 

 simple or 3-forked spines. Leaves abruptly bipinnate, alternate or fascicled from 

 earlier axils, short-petiolate, the rachis short and spinescent, with 2-4 secondary 

 elongated rachises bearing numerous minute opposite entire leaflets without stipels; 

 stipules short, persistent and spinescent, or caducous. Flowers on thin elongated 

 jointed pedicels from the axils of minute caducous bracts, in slender axillary solitary 

 or fascicled racemes; calyx short-campanulate, 5-lobed, the lobes slightly imbricated 

 or subvalvate in the bud, narrow, membranaceous, nearly equal, becoming reflexed, 

 deciduous; petals bright yellow, unguiculate, much longer than the lobes of the 

 calyx, spreading, the upper one rather broader than the others and glandular at the 

 base of the claw; stamens 10, inserted in 2 rows on the margin of the thin disk, 

 free, slightly declinate, those of the outer row opposite the sepals and rather longer 

 than the others; filaments villose below the middle, the upper one enlarged at the 

 base and gibbous on the upper side; anthers uniform, versatile; ovary short-stipi- 

 tate, pilose, contracted into a slender filiform incurved style infolded in the bud and 

 tipped with a minute stigma; ovules numerous, suspended from the inner angle of 

 the ovary. Legume linear, torulose, acuminate at the ends, 2-valved, the valves thin 



