508 SIR JOHN LUBBOCK ON STIPULES, 
The petioles are semiterete, flattened above, and furnished 
with a ligula or outgrowth from the base of the upper face, pro- 
tecting the bud. This ligula is triangular, obtuse, pale green, 
1'5-2 mm. long ; collectively they form a whorl, covering all but 
the extreme apex of the bud (fig. 5). 
Fig. 5. 
Alstonia scholaris.—Terminal whorl of leaves to show ligules covering the bud. 
(Reduced about }.) 
Groom (Trans. Linn. Soc. ser. 2, Bot. iii.) compares the ligule 
with the ledge-like stipular process of Zabernemontana, and 
describes the manner of bud-protection in 7. dichotoma (p. 261). 
In Apocynum androsemifolium, Linn., the petioles are grooved 
or concave. The terminal buds are protected by a pair of leaves 
which are opposite or nearly so. The stipules are subulate, 
glandular, and occupy the spaces between the narrowed bases 
of the leaves. The winter-buds are subterranean, generally 
numerous, and protected by leaves reduced to the condition of 
