6 GENERAL MORPHOLOGY 



and function. These appendages, whatever their form or use, 

 accord with leaves in mode of origin, position, and arrangement 

 on the axis or stem. Their most general and ordinary form is 

 the familiar one of foliage ; hence the name of leaves has been 

 by botanists extended in a generic way from the green expan- 

 sions which constitute foliage to other forms under which such 

 appendages occur. The proper morphological expression is, 

 that the latter are homologous with leaves, or are the homologues 

 of leaves. 1 



13. Leaves are borne upon the stem at definite places, which 

 are termed NODES. A node may bear a single leaf or a greater 

 number. When it bears two, they occupy opposite sides of 

 the stem. When three, four, or more, they divide the circum- 

 ference of the stem equally, forming a circle, technically a 

 WHORL, or in Latin form a VERTICIL. When only two, the pair 

 evidently answers to the simplest kind of whorl. So that leaves 

 are either single on the nodes, in which case they are alter- 

 nate, that is, come one after another on the stem ; or in whorls 

 (whorled, verticiUate) , in the commoner case of a single pair 

 being called opposite. The bare space between two successive 

 nodes is an INTERNODE. This is longer or shorter, according to 

 the amount of longitudinal growth, which thus spaces the leaves, 

 or whorls of leaves, in most various degrees, either widely when 

 the internodes are elongated, or slightly when they remain very 

 short. The plant, therefore (roots excepted) , is made up of a 

 series of similar parts, i. e. of portions of stem, definitely bearing 

 leaves, each portion developed from the apex of the preceding 

 one. This constitutes a simple-stemmed plant. 



14. Branching is the production of new stems from the older 

 or parent stem. These normally appear in the AXILS of leaves, 

 that is, in the upper angle which the leaf forms with the stem, 

 from which they grow much as the primary stem grew from the 

 seed. The primary stem, connected with the ground, produces 

 roots which develop downwardly into the soil, from which they 

 draw sustenance. Branches, when developed above ground, 



1 A common designation for all these appendages being desirable, a good 

 one is furnished by the Greek name for leaf, <pt\\ov, PHYLLUM, plural 

 PHYLLA. This, used with prefixes, may be made to designate the kind of 

 leaves in many cases, as, prophylla, catapky/la, hypsophylla. 



Recent German botanists use the word Phyllome in this sense. It is a 

 rather convenient and well-sounding word ; but phylloma is the exact Greek 

 equivalent of our word foliage, and therefore not very well chosen as a 

 common term for leaves which are not foliage as well as those which are. 

 Nor will this word, like phyllum, readily take prefixes, as above, or the adjec- 

 tive form, as it readily does in prophyllous, hypsophyllous, gamophyllous, &c. 



