INTRODUCTION 
Margin 
Base 
or secondary pinna?, or the ultimate divisions are termed pinnules. If, 
however, a leaf be cut up into innumerable very fine segments, as in the 
Carrot, Fennel, Water-crowfoot, and some other submerged plants, it is 
termed decompound. 
If the margin of a leaf is free from any indentations, as in the Lily-of- 
the-valley, it is termed entire ; if wavy, as in the Oak, sinuate ; if scalloped, 
with rounded scallopings, as in the Violet, crenate ; if 
toothed with teeth pointing outwards, dentate; if pointing 
backwards towards its base, as in the Dandelion, runcinate ; or if, as is 
much more frequent, pointing upwards, serrate. It will be noticed that 
the serrations may be even, as in the Rose and the Linden, or irregular, as 
in the Hazel, or may be themselves once or twice toothed {hi- or tri-serrate ), 
as in “ cut-leaved ” varieties of many trees. 
Among descriptive terms applied to the base of the leaf the more 
important are cuneate or wedge-shaped, as in the Plane ; attenuate , with 
the blade tapering down along the stalk, as in the Daisy; 
and cordate or heart-shaped, as in the Water-lilies. The 
projecting lobes at the base of the blade in such leaves as these last 
are called auricles (Latin auricula , a little ear), and these auricles are 
often unequal in size, the one towards the centre of the bud having less 
room to develop. This produces the oblique base seen in the Linden, 
Elm, and Hazel, and, among cultivated plants, in Begonia. If a sessile 
leaf is cordate, it is sometimes termed auriculate , whilst if its auricles, 
owing to more luxuriant growth, overlap one another, the leaf is called 
amplexicaul (Latin amplexus , embraced ; caulis , stem). If the auricles 
grow together, so that the stem appears to be growing through the 
leaf, the latter is, somewhat absurdly, called perfoliate , and a little-known 
group of plants, the Hare’s-ears ( Bupleurum ), derive from this character 
their Old English name of Thorow-wax. If the auricles adhere to 
the stem below the base of the leaf, as in most Thistles, the leaf is 
termed decurrent. Pointed auricles extending downwards make the leaf 
sagittate , or arrow-shaped, as in the beautiful water-plant called for this 
reason Arrow-head ; whilst if they point outward, as in some Docks, 
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