INTRODUCTION TO BOTANY. vil 
Leaves are, 
deltoid, equilateral-triangular, or shaped like a Greek A: when ap- 
plied to the tooth of a calyx, the base of the triangle is sup- 
posed to rest on the calyx tube. 
spathulate, when the broad part near the top is short, and the nar- 
row, tapering part long, compared to a spatula, or flat ladle. 
oblong (or broadly linear) when 2-4 times as long as broad, with 
subparallel sides and blunt extremities ; 
ovate, when about twice as long as broad, broader below the middle, 
or shaped like the longitudinal section of an egg; obovate is 
the same form reversed, the narrow end being at base. 
orbicular, or rotund, when approaching to a circular form. 
oval, or elliptical, when broadest in the middle, with curved sides, 
like an ellipse, or oval. 
transversely oblong, or oblate, when conspicuously broader than long. 
rhomboidal, or rhomboid, when shaped like the mathematical figure 
called a rhombus. 
faleate, shaped like a scythe, curved with nearly parallel sides and a 
sharp point. 
44, Intermediate forms are expressed by combining two terms. Thus, 
a linear-lanceolate leaf is long and narrow, yet rather broader below the 
middle and tapering to a point; ovato-lanceolate is broad towards the base, 
yet tapering towards the apex, etc. 
45. The apex or summit of a leaf is, 
acute, or pointed, when it is sharp, or forms an acute angle. 
obtuse, or blunt, when it forms an acute angle or oftener is rounded. 
acuminate, when suddenly narrowed near the top and then pro- 
longed into an acwmen, or projecting point, which may be acute 
or obtuse, linear or tapering; cuspidate is either synonymous 
with acuminate, or else used to express a more exaggerated 
degree of acumination, with a more sudden, sharper, and more 
rigid point. 
truncate, when the end is cut off nearly square. 
retuse, en very obtuse or truncate, and slightly indented in the 
middle ; 
emarginate or notched, when more decidedly indented at the end of 
the midrib. 
mucronate, when the midrib is produced beyond the apex in the 
form of a small point; mucronulate when it projects very little. 
aristate, when the point is long and fine, like a bristle. 
46. The base of the leaf is liable to the same variations of form as the 
apex, but the terms commonly used are tapering or narrowed for acute and 
acuminate ; rownded for obtuse; and cordate for emarginate. But the term 
cordiform, cordate, or heart-shaped leaf, is restricted to an ovate and acute 
leaf, cordate at base, with rounded auricles; and odcordate to an obovate, 
deeply emarginate or subbilobed leaf or leaflet, with rounded lobes. The 
word auricle is more strictly applied to the prolonged base of sessile and 
stem-clasping leaves. 
47. If the awricles (46) are pointed, the form is said to be sagittate when 
the points are directed downwards, as in the head of an arrow; hastate, 
when the points diverge horizontally, compared to a halbert. 
48. A reniform leaf is broader than long, very obtuse at apex, slightly 
but broadly cordate at base, with rounded auricles, compared to a kidney. 
49. In a peltate leaf, the stalk, instead of proceeding from the lower 
edge of the blade, is attached to the under surface, often near the lower 
edge, but sometimes in the very centre of the blade; the nerves radiate 
from the point of attachment of the petiole, or proper base of the leaf. It 
