. ZYGOPHYLLACEAE. 



GUAIACUM. Lignum Vitae. 

 (Family Zygophyllaceae). 



Trees with very hard yellow 

 wood and resinous bark: ever- 

 green. Twigs rather slender, 

 forking at short intervals, green, 

 subterete: pith small, round, con- 

 tinuous, white. Buds scarcely dis- 

 cernible, not evidently scaly ex- 

 cept as the abortive end-bud may 

 show several stipules. Leaf-scars 

 opposite but the pairs not decus- 

 sating, broadly crescent-shaped, 

 somewhat elevated by the swollen 

 nodes: bundle-trace 1, indistinct: 

 stipules rather persistent, one of 

 each pair overlapping the other. 

 Leaves abruptly pinnate, with sev- 

 eral pairs of rather large entire 

 leaflets. 



In his collected essays On Buds 

 and Stipules Sir John Lubbock 

 who subsequently became Lord 



Avebury pictures twigs of Guaiacum which have the leaf- 

 pairs decussating in the normal manner. 



Stipules blunt: leaflets prominently veiny. 

 Stipules pointed: leaflets obscurely veiny. 



(1). G. officinale. 

 (2). G. sanctum. 



