

ANALYTICAL KEY TO THE GENERA XXV 



Leaflets deltoid to hastate, entire, rounded at apex; branches prickly. 



Erythrina (p. 627). 



Leaflets ovate to oblong, acuminate, strongly scented and bitter; branches unarmed. 



Ptelea (p. 639). 

 ** Leaves twice pinnate; stipules present. 



a Leaves unequally twice pinnate, 2-4 long, deciduous; leaflets serrate, 2'-3' in length; 



branches and stem armed with scattered prickles. Aralia (p. 778). 



aa Leaves equally twice pinnate, usually smaller; branches unarmed or armed with stipu- 



lar or axillary spines (in Parkinsonia often apparently simply pinnate) . 

 b Leaflets crenate; leaves simply or twice-pinnate on the same plant, deciduous, 

 usually armed with simple or branched axillary spines. Gleditsia (p. 607). 

 66 Leaflets entire. 



Leaflets 2-2^' long; leaves deciduous; branchlets stout, unarmed. 



Gymnocladus (p. 605). 



Leaflets smaller; leaves usually persistent; branchlets slender. 

 Branches armed with prickles or spines. 

 Leaves with 2 or rarely 4 pinnse. 



Branches armed with axillary spines or spiny rachises. 



Pinnse with 4-8 leaflets; branches with short axillary spines. 



Cercidium (p. 613). 



Pinnse with 860 leaflets; branches armed with spiny rachises or rigid 

 branchlets terminating in stout spines. Parkinsonia (p. 611). 



Branches armed with stipular prickles; leaves persistent. 



Pinnae with many oblong to linear leaflets. Prosopis (p. 599). 



Pinnse with 1 pair of orbicular to broad-oblong leaflets. 



Pithecolobium unguis-cati (p. 586). 

 Leaves with 6, or more, rarely 4, pinnse. 



Prickles usually spreading, often recurved. Acacia (p. 591). 



Prickles usually more or less ascending, straight. Pithecolobium (p. 586). 

 Branches unarmed. 



Branchlets and petioles glabrous; leaves with 2-5 pair of pinnse, each 

 with 40-80 leaflets. Lysiloma (p. 589). 



Branchlets and petioles pubescent while young; leaves with 5-17 pair of 

 many-foliolate pinnse, or pinnse 2-4 and each with 8-16 leaflets. 



Leucaena (p. 596). 



*** Leaves simply pinnate. 



a Leaves equally pinnate. 

 Stipules wanting. 



Leaflets 2-4, generally oblong-obovate. Exothea (p. 714). 



Leaflets 6-12. 



Leaflets obtuse, usually oblong-obovate. 



Leaflets 8-12, 2'-3' long, pale below; leaves occasionally opposite. 



Simarouba (p. 642). 



Leaflets 6-8, I'-l^' long, green below. Xanthoxylum coriaceum (p. 637). 

 Leaflets 6-8, acuminate. Swietenia (p. 648). 



Stipules present. 



Branches armed with infra-stipular spines in pairs; leaflets 10-15, usually oblong- 

 obovate, \'-\' long, persistent. Olneya (p. 626). 

 Branches unarmed; leaflets 20-46, ovals '-' long. Eysenhardtia (p. 620). 

 aa Leaves unequally pinnate. 

 6 Stipules present. 



Leaflets sharply serrate; leaves deciduous; winter-buds resinous. 



Sorbus (p. 390). 



Leaflets entire or crenately serrate. 

 Leaves deciduous. 



Leaflets 7-11, 3'-4' long; branches unarmed. 



Leaflets usually alternate, thin and glabrous at maturity. 



Cladrastis (p. 618). 



