Definitions. xxxi 



composed of 3 separate leaflets, are called trifoliate ; l those with 5 

 or 7 leaflets are expressed in this work as 5-foliate or 7-foliate. 



16. A pinnate leaf is one composed of more than 3 leaflets arranged 

 on each side of the midrib, or common petiole. If the number of 

 leaflets be even, the leaf is said to be evenly or abruptly pinnated ; 

 if uneven, unevenly or unequally pinnated. In this case the odd 

 leaflet is often called the terminal one. 



The divisions of pinnate leaves are themselves sometimes pinnate, 

 as in many of the Acacias. The leaf is then called decompound, or 

 bipinnate, or tripinnate, as the case may be : the pinnce are. then the 

 larger divisions of the leaf, the leaflets the divisions of the pinnae. 



Note, that leaflets may have all, or nearly all, the characteristics 

 of simple leaves, i.e. they may be sessile or petioled, opposite or 

 alternate on the common petiole or midrib, and may be very various 

 in shape and the outline of their edges. 



17. The edges of leaves. When the edge is even, and without teeth 

 or depressions of any sort, the leaf is entire; when it has small, 

 sharp teeth, like a saw, it is serrate ; if the teeth are rounded it is 

 crenate ; if deeply notched, dentate; if the edge is not toothed, but has 

 broad and shallow depressions, the leaf is sinuate ; if the depressions 

 are shallower and less marked it is wavy or undulate ; if the leaf ia 

 fringed with hairs it is ciliated. The above terms are also applied 

 to petals, sepals, bracts, etc. The term pectinated, implying that the 

 teeth are long and narrow, like a comb, is applied oftener to these 

 smaller organs than to leaves. 



18. The shape of the leaf. The number of terms used in botany to 

 express the different shapes of leaves is exceedingly great, but the 

 following will, it is thought, be sufficient in a work of this sort. 



The narrowest possible leaf, not tapering to either end, is called 

 linear, though, of course, every leaf must have some breadth ; equally 

 narrow, but tapering to a point, subulate or awl-shaped ; a narrow 

 leaf, shaped like the head of a lance, is lanceolate; an egg-shaped leaf, 

 i.e. broader than lanceolate and broadest in the middle, is oval 

 (ovate is used variously by different authors, but may be taken as 

 approaching oval, but broader) ; elliptic may be taken as something 

 between oval and lanceolate ; when the upper end is decidedly the 

 broadest the leaf is obovate ; when the leaf does not broaden in the 

 middle it is oblong ; when it tapers sharply from the middle to the 

 base it is cuneate, or wedge-shaped; spathulate (ladle-shaped) when 

 the top is broad, and the lower and narrow part long ; heart-shaped, 

 which explains itself, implies that the broad part is nearest the 

 petiole or stem ; cordate is applied to a leaf of any shape, if its base 

 belike the broad part of a heart; kidney-shaped, or reniform, is 

 roundish, broader than long, and cordate ; falcate is curved, like the 

 blade of a sickle. When the lower part of the leaf is prolonged 

 into two acute lobes, it is called sagittate, or arrow-shaped ; when 

 these lobes are not acute, but rounded, and more or less ear-shaped, 

 it is auricled. When the two sides of a leaf are unequal it is called 

 oblique ; this is often the case at the base of the leaf only. 



1 I retain this rather than the modern and more correct word 

 trifolioliate, which seems needlessly pedantic for my purpose. 



b 2 



