ORGAN. Stem, leaf, bud, etc. 



OUTER. The direction away from the base of the leaf or the twig. 



OVAL LEAF. Here used to indicate either an ellipse, like the letter O, 

 or an egg-shaped figure. In any case the opposite margins curve 

 and the leaf is not so narrow as an oblong leaf. 

 PALMATELY COMPOUND. Divided into leaflets radiating from the 

 tip of the petiole and separate from each other. The leaflets are 

 pinnately veined. 

 PALMATELY LOBED. A margin deeply cut into segments which are 

 united at the base of the leaf like fingers at the palm of a hand. 

 Palmately veined. 

 PALMATELY VEINED. Several large veins of almost equal size ra- 

 diating from the base of the leaf. 

 PARALLEL-VEINED. The smallest veins in the leaf running almost 

 in the same direction. Contrasted with netted-veined. Best seen 

 by holding a leaf up to the light and looking through it. 

 PEG. A stif? stalk attached more closely to the cushion from which it 

 grows than to the leaf which it supports. Often a different color 

 from the leaf proper. 

 PETIOLE. The stalk of the leaf; belonging to it and falling with it in 



simple leaves. Not all leaves have petioles. 

 PINNA. Here used to denote that part of a doubly compound leaf 

 which corresponds to a leaflet. It is usually made up of secondary 

 leaflets. 

 PINNATELY COMPOUND. Divided into leaflets which are separate 

 from each other but united to the rachis (the part which corre- 

 sponds to the midrib). 

 PINNATELY LOBED. Having deep indentations which run almost to 



the midrib of a pinnately veined leaf. 

 PINNATELY VEINED. Feather-like. Having a strong central vein, 



the midrib, from which branch side veins. 

 PITTED. Marked with little spots or holes. 

 POINTED. Sharp-tipped. 

 PRICKLE. A sharp-pointed outgrowth of the outer covering of a twig 



or branch. Not usually found at a node. 

 RACHIS. The middle part of a pinnately compound leaf. The leaflets 



are attached to it. It corresponds to the midrib of a simple leaf. 

 RANKS. The longitudinal rows in which leaves and leaf-scars are ar- 

 ranged. To determine use a string as described in SPIRALLY 

 ARRANGED, or look down the twig from the tip. 

 RESINOUS. Here used as a synonym of sticky. The substances re- 

 ferred to as resin are found especially in young leaves, buds and 

 twigs. They are often located in dots on the leaf-blade. 

 SCALELESS. Without bud-scales. The contents are visible, but are 

 usually so covered with hairs that their outlines are obscured and 

 they are sometimes taken for fuzzy scales. 



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