12 PLANTS: THEIR NATURAL GROWTH 



parts are thrown off at intervals along the central line : of this type the Ash is a good example ; 

 we see it also very well shown in fig. 2 1 7. Such leaves are termed pinnate, from the Latin word 

 pinna, a feather. The leaflets composing them may be all of very similar size, or the difference 

 amongst them may be very mafked, as we see in the Agrimony leaf, fig. 258. When the divisions 

 into which a leaf is cut up become very numerous and complex in their arrangement, the leaf is 

 said to be decompound ; while a still greater cutting up of the parts, as in the Hemlock (Conium 

 maculatum), renders it supradecompound. 



The character of the outline of the leaf is a point of considerable importance to the orna- 

 mentist. If bounded by one continuous and unbroken line, as in the Lilac (Syringa vulgaris, fig. 

 55), and in the design fig-. 323, the leaf is said to be entire. If the outline appears like a series 

 of teeth, as we see it in the Violet leaf, or that of the Sycamore (fig. 36), it is said to be serrate 

 (Lat. serra, a saw). We have this feature introduced in the design marked 320. It is capable of 

 giving great richness of form and effect in an ornamental composition. When similarly-shaped 

 teeth— instead of all being directed, as in the serrate form, towards the apex of the leaf or lobe- 

 are directed outwards merely from the centre of the leaf, and approximately perpendicular to its 

 general outline, they are said to be dentate (Lat. dens, a tooth). If these teeth are rounded, as in 

 fig. 222, they are called crenate. When these three forms of teeth are very small the leaf is 

 serrulate, dentulate, or crenulate. The term erose (Lat. erodo, to gnaw off), is applied to leaves in 

 which the margin is irregularly cut, as in the Ragwort (Senecio Jacobcza). Other terms are 

 occasionally given in works, and used in botanical descriptions, but they are of less importance, 

 both in themselves and to the special purpose of the ornamentist, than those given above. 



The venation of the leaf becomes another ornamental feature : we need, however, dwell 

 but a short time upon it Leaves have their veins parallel (not in a mathematical sense) when 

 they run, as in the leaves of the Iris or Yellow Flag (Iris pseud-acorus), from one extremity of 

 the leaf to the other. They have their veins reticulated (Lat rete, a net) when they branch and 

 form a net work, as in the Apple (Pyrus malus), and most other trees and herbs. They are said 

 to be bifurcated when the veins, as in Ferns, regularly branch off into pairs (Lat. bis, twice, 

 and /urea, a fork). In reticular venation the leading veins may be either penninerved or palmi- 

 nerved ; there are other smaller divisions, but this general and broad classification will suffice for 

 the purposes of the ornamentist : penninerved, when approximately parallel lines are given off in 

 succession, at intervals, upon the central line ; and palminerved, when the principal ribs all start 

 in a radiate form from the base of the central line, like a hand with the fingers extended. The 

 Oak (Quercus robur) is an example of the first form : the Vine leaf ( Vitis vinifera) of the second. 



The texture of the leaf is not a matter of much importance in surface decoration, but in 

 relief work it is not unworthy of consideration. Some leaves are very thin and dry ; others, 

 though thin, are pliable; others again, soft and flexible. Some, like the House-leek ( Sempervivum 

 tectorum), are thick and fleshy. Others again, like the Mistletoe ( Viscum album), are dense and 

 leathery. In most leaves a certain flatness of surface is a characteristic ; but in some, as the 

 Weld (Reseda Luteola), the margin is waved — a valuable feature frequently in relief work. In 

 some cases, as, for instance, the Wood-sage (Teucrium scorodonia), and the Coltsfoot (fig. 42), the 

 whole surface of the leaf is wrinkled into convex masses between all the principal veins. 



As it would be impossible, while keeping our volume of a reasonable bulk, to give plates 

 of the entire growth of each plant we mention, or even of those of which at present some single 

 detail — a flower or leaf — is given, we desire, while making some few and brief remarks respecting 

 each, to also indicate where the student may turn for fuller information. To this end we are 

 careful, in mentioning any plant, to give with its familiar name, that also by which it is known 

 botanically , not that it will, in this place, be of much value, but expressly as a means of finding 

 it in other works to which it may seem desirable to refer. All the books to which we now desire 

 to call attention will, we believe, be found, together with many others quite as valuable, in the 

 Art Library of the Department of Science and Art, South Kensington Museum, where they can 

 be consulted at a fee so small as to become almost nominal, in comparison with the advantage to 

 be derived — a payment of sixpence entitling any person to avail themselves of the full advantages 

 of the fine collection of art- works there accumulated, for one week, and at a rate even lower for a 

 longer period ; while those who, from their residence away from London, are unable to profit in 

 the full advantage, can, by joining the classes of any provincial School of Art, of which there is 

 one in every town of any size throughout the Kingdom, have almost equal privilege, as the 

 masters of such schools have the power of borrowing, at will, from the central collection. The 

 books to which we would more especially desire to refer our readers are as follows : — The Flora 

 Londinensis, of Curtis : this, though published many years ago, is an excellent work for the 

 designer. The plates are very large, and in almost all cases the whole plant is represented. 

 The illustratrations are very carefully drawn and coloured. Though limited to the plants found 



