62 NATURAL HISTORY OF PLANTS. 



thick {Anonycldum), sometimes elongated plano-convex or moniliform 

 {Algarobia), more rarely irregularly thickened, corrugated twisted 

 {Adenosis) ; indehiscent ; endocarp cartilaginous or papyraceous, 

 usually produced into septa between separate seeds, more rarely con- 

 tinuous by disappearance of septa; mesocarp thin or more usually 

 thick, spongy. Seeds ovate or oblong, compressed. — Trees or shrubs, 

 prickly, usually armed with axillary spines ; leaves 2-pinnate ; pinnae 

 1-, 2-, or rarely cc-jugate; leaflets often somewhat rigid, pauci- or 

 multi-jugate ; stipules small or ; flowers in solitary or fascicled 

 axillary racemes spikes or globose heads {All tropical and subtropical 

 regions). — See p. 28. 



11. ? Xerocladia Harv. — Flowers 5-merous (of Prosopis) ; calyx 

 deeply cleft; petals cohering below the middle. Stamens shortly 

 exserted. Ovary 1- or pauciovulate. Legume sessile piano-com- 

 pressed indehiscent, 1-2-seeded, " broadly falciform -ovate or semi- 

 orbicular, bowed tapering winged at inferior suture." A small shrub, 

 rigid much-branched ; leaves few 2-pinnate ; pinnae 1-2-jugate ; 

 leaflets small pauci-jugate ; stipules spinescent curved ; flowers in 

 short subcapitate axillary spikes; peduncle short {Southern Africa). — 

 See p. 29. 



12. Dichrostachys DC. — Flowers 5-merous differing in colour, 

 hermaphrodite or polygamous, inferior neuter. Calyx toothed. 

 Petals cohering below the middle, valvate. Stamens 10 ; filaments 

 in hermaphrodite flower free slender; in neutral and female petaloid 

 or filiform, elongated coloured : anthers introrse, crowned by a stipi- 

 tate gland, in neutral and female flowers small or sterile or usually 0. 

 Gynaeceum of Prosopis. Legume linear compressed twisted coriaceous 

 indehiscent, continuous within ; valves rarely separating irregularly 

 from sutures. Seeds obovate compressed. — Shrubs ; twigs often 

 short, sometimes spinescent leafless ; leaves 2-pinnate, often fascicled 

 on floriferous branches; leaflets small co-jugate; stipules small or 

 deciduous, or on floriferous twigs, broader imbricated; flowers in 

 spikes ; spikes cylindrical pedunculate, solitary or geminate, often 

 nutant, either axillary or terminal on very short fascicled-leaved 

 twigs; upper flowers hermaphrodite, lower neuter, middle often 

 unisexual {Tropical Asia, Africa, and Australia). — See p. 29. 



