164 NATURAL HISTORY OF PLANTS. 
caducous (Hot regions of America, Memico, southern Africa). 
See p. 77. 
5. Cercidium Tun.—Flowers of Cesalpinia; sepals subequal, 
valvate or subimbricate with obliquely-cut margins. Stamens 10; 
filaments pilose at base; anthers uniform ovate versatile. Germen 
shortly stipitate, o-ovulate; style involute, apex acute; stigma 
small terminal. Legume linear-oblong plano-compressed, mem- 
branous or subcoriaceous, 2-valved; sutures nerviform ; valves venu- 
lose. Seeds ovate compressed albuminous.—Trees or shrubs ; 
branches usually tortuous; axillary twigs spinescent ; leaves small 
2-pinnate ; leaflets small paucijugate ; flowers fascicled in short lax 
racemes at defoliated nodes of wood; bracts small membranous ; 
bractlets small or 0 (Central America, Mexico). See p. 77. 
6. Mezoneurum Desv.—F lowers of Cesalpinia; receptacle cupuli- 
form or obliquely cymbiform, glandular within, sometimes subrostrate 
posteriorly. Sepals 5, unequal (lowest sepal usually much the 
largest) free, finally spreading or coalescing into a rather long 
tube, much imbricated. Petals of Cesalpinia; highest petal 
innermost, usually unlike the others, sometimes having within 
above the base a small unequally-corrugated laciniate appendix. 
Stamens 10; filaments glabrous or pilose at base. Germen 2—c- 
ovulate; style usually clavate at apex; stigma terminal small, 
usually concave minutely ciliate. Legume plano-compressed, 
membranous or coriaceous, longitudinally winged at superior suture, 
indehiscent or sub-2-valved. Seeds transverse plano-compressed, 
orbicular or reniform; embryo exalbuminous; cotyledons flat ; 
radicle short straight.—Trees or more frequently high climbing 
shrubs, often prickly ; leaves 2-pinnate; stipules small or 0; flowers 
in axillary simple or terminal compound racemes; bracts usually 
caducous ; bractlets 0 (Zropical Asia, Africa, and Australia). 
See p. 78. 
7. Hematoxylon L.—Flowers subregular; receptacle cupuli- 
form subhemispherical, glandular within. Sepals 5, subequal, much 
imbricated. Petals 5, oblong spreading subequal imbricated. Stamens 
10, perigynous uniform; 5 oppositipetalous shorter. Germen 
inserted in bottom of receptacle, free, shortly stipitate, pauci- 
