12. Two short
(< 2 cm) unbranched thorns at a node, one at either
side of each leaf scar, and best developed on young, fast-growing
twigs, not present on mature trunks; well-developed leaflets
more than 1 cm broad.
12.
Thorns single , located
above the leaf scar; often much longer than 2 cm and sometimes
branched, also present on trunk
and older branches; leaflets less than 1 cm wide.
