THEIR FORMS AND FUNCTIONS. 528 
or their sheaths were, in some ancestral form, connate by their 
edges and decurrent upon the stem in the form of wings as 
we see in some of the Composite. The leaves of Carduus are 
strongly decurrent upon the stem, but they are alternate. 
Before rising out of the ground the flowering-stem is bent like 
that of a germinating seedling. 
The first pair of leaves are sometimes reduced to small scales, 
so that they with their stipules form a whorl of six scales 
surrounding the stem, as in species of Galium, Rubia, and others 
of that tribe. 
In Mercurialis annua, Linn., the stipules are subulate, acute, 
membranous, of a pale white, and inserted upon the stem at the 
very base of the petioles, and falling rather early. The leaves 
protect one another and are involute in the bud. The stipules 
also assist in protecting the terminal bud, but they seem of more 
importance in protecting axillary buds in their young stages. 
In Dalechampia Roezliana, Muell. Arg., the stipules are large 
(9 mm. long, 4mm. wide), ovate, acute, many-nerved, with a strong 
midrib, inserted on the stem with a broad base, red when young, 
and persisting on the stems in a brown and withered condition 
long after the persistent leaves themselves have fallen. 
The terminal buds are completely enclosed by each pair of 
stipules in succession, the latter come in contact by their flat, but 
perfectly free edges. The stipules are fully developed or nearly 
so while still in the bud, and exceed as well as enclose the leaf 
to which they belong. When a pair is sufficiently old to commence 
expansion, the enclosed leaf is seen to be folded along the middle, 
involute at the edges, incurved at the slender tip, and of con- 
siderable size. 
Axillary leaf-buds are not very frequent, but they would be 
well sheltered by the stipules even if their development were 
delayed till after the fall of the leaf. 
Axillary buds consisting of successively developed inflores- 
cences are frequent and are amply sheltered by the stipules. 
Below the flowers are two large, opposite, coloured bracts, which 
become green, and each has a pair of stipules which close the space 
between the bracts and even overlap one another. 
URTICACER. 
In Chlorophora tinctoria, Gaudich., the leaves are small, lanceo- 
late-elliptic, alternate, petiolate, stipulate; the petioles short, 
