i8 SIMPLIFIED LEAVES 



(i) It does not arise in the axil of a leaf j on the contrary, 

 it has a bud in its axil. 



(2) Often it possesses two stipules at the base of its stalk 

 — e.g. Rose, Pea (fig. 59 n). 



(3) The leaflets do not necessarily arise in acropetal succes- 

 sion on the stalk of the compound leaf, neither does the 

 latter terminate in a bud. 



(4^ The leaflets have no buds in their axils. 



(s) A leaf is always lateral on an axis, but a leaflet may 

 be terminal on a leaf-stalk — e.g. Rose. 



When the leaflets are ranged along the sides of an 

 elongated stalk, the leaf is said to be pinnately-compound 

 (fig. 23) — e.g. Rose, Pea. On the other hand, when the 

 leaflets spring from a single point at the summit of the stalk, 

 the leaf is digitate (fig. 27) — e.g. Clover and Strawberry, with 

 three leaflets (fig. 54), Horse-chestnut with about seven 

 leaflets. 



SIMPLIFIED LEAVES. 



Some leaves are much simpler than the green foliage-leaves. 

 They may be described as simplified leaves, and be arranged 

 under four heads : Scales, Cotyledons, Prophylls, and Bracts. 

 Usually they are not difierentiated into sheath, stalk, and blade; 

 frequently they represent merely parts of complete leaves. 



SCALES. 

 Scales are small, simple leaves, usually with even (entire) 

 margins. They possess littie or no green colouring-matter, but 

 are brownish or pale in colour. They are without stalks, and 

 are attached to the stem by a relatively broad base. Scales 

 occur upon parts of the stem which are above ground in the 

 form of bud-scales, as in the Hazel and Oak, or quite apart from 

 the buds, as in the Scotch Pine and Asparagus. But they are 

 also present on subterranean stems, as in the Hyacinth, some 

 Grasses, and Potato-tubers. Scales are therefore not defined 

 by their position on the stem. A scale may represent the 

 persistent base of a foliage-leaf, the upper portion of which has 

 died away (as in some bulbs) ; in other cases the scales may 

 be arranged in pairs, and are merely the stipules of leaves the 

 blades of which never develop (as in the resting-buds of the 

 Hazel) ; finally, some scales represent complete leaves (as in 

 the bulb of a Lily). 



