THEIR FORMS AND FUNCTIONS. 515 
stipules, which are membranous, closed at the top, and longer 
than the buds, thus forming so many caps over them and answer- 
ing the purpose of scales as seen in deciduous trees, but without 
the apical prolongations. Succeeding leaves are perfect, with 
the lamina protected as in the growing bud. Growth is resumed 
by these axillary buds only. 
The prolongations of the ocree in the bud stage are repre- 
sented by two short teeth, which elongate on the resumption of 
growth. 
In Polygonum equisetiforme, Sibth. & Sm., the leaves are 
aiternate, sessile or subsessile, small, linear, strongly and per- 
manently revolute at the margin. 
The ocreate stipules are adnate to the petiole or leaf for half 
their length, and connate into a cylindrical sheath 2-4 mm. 
long, closely fitting the stem, and terminating in numerous 
subulate, membranous teeth or fringes } to 3 as long as the 
sheathing portion. The latter is green and striated exactly like 
the stem, and is persistent ; the terminal fringe soon becomes 
brown, though pale and scarious at first, and gets variously torn 
and broken away. The stipules may be described as slightly 
intrapetiolar, seeing that they are connate for a very short 
distance in front of and above the insertion of the leaf upon the 
sheathing portion. 
The leaf is not protected by its own stipules, but by those of 
the next older leaf or leaves. The terminal bud forms a small 
cone covered by the stipules of several leaves, and the scarious 
portion lies over the top. From this cone the leaves emerge in 
succession, but never expand or alter their form. 
The axillary buds are protected by the sheathing portion of 
the ocrex till they attain some size, and likewise by numerous 
stipules belonging to their own axis. 
In Muehlenbeckia platyclada, Meissn., the leaves are alternate, 
distichous, shortly petiolate, stipulate, oblong and entire or 
hastate, and are inserted on the edges of the stem, and deciduous 
or even caducous; the petioles are short, tapering to the base, 
and slightly winged or sometimes very little developed. In 
many cases the lamina and petiole are wanting. 
The ocrew or stipules are adnate to the petiole at the base 
only, and then becoming free, intrapetiolar, closely investing the 
stem and connate; they are very thin, membranous, hyaline, 
and often difficult to distinguish from the stem, although on the 
LINN. JOURN.—BOTANY, VOL. XXX. 20 
