40 MORPHOLOGY 



altogether without hairs. In the latter case the leaf 

 is said to be GLABROtrs. 



In consistency a leaf may be fleshy and more or 

 less brittle, as pathar-kucha and him-sagar; or soft 

 and leather-like, as India-rubber, Sapota {Achras 

 Sapota), gab (Diospyros Embryopteris), pun -nag 

 {Calophyllum), kadamba {Anthocephalus Cadamba), 

 nageswar {Ochrocarpus longifolius). In the latter 

 case the leaf is said to be coriaceous. If a leaf is 

 held against the sun, it is found that in some cases, 

 as in Orange, kamini (Murraya exotica), kala-jam, 

 Hypericum, the blade is dotted with pellucid glands 

 or dots filled with an essential oil. In fact, these 

 glands are characteristic of the plants belonging to 

 the Orange, Hypericum, and jam family. 



A leaf may have one blade, or more than one; in 

 the former case the leaf is said to be simple, and 

 in the latter case compound. In compound leaves 

 the blades are usually small, and are therefore called 

 LEAFLETS. Compound leaves are of two types, 

 namely, pinnate and palmate. In pinnate leaves 

 the petiole is prolonged into an axis known as the 

 rachis, on either side of which the leaflets are 

 arranged either alternately or in opposite manner. 

 The rachis or axis may be simple, bearing leaflets on 

 either side; or it may give rise to secondary rachises 

 or axes on either side (instead of leaflets), and these 

 secondary rachises bear leaflets: or the secondary 

 rachises, in their turn may give rise to tertiary 

 rachises or axes (instead of leaflets), and these 

 tertiary rachises bear leaflets in their turn. Accord- 

 ingly the pinnate leaves are either simply pinnate 

 (fig- 39), bipinnate (see fig. 64), or tripinnate (fig. 

 40). If the rachis is further branched before bearing 

 leaflets, the leaf is said to be decompound. The 



