AND ORNAMENTAL TREATMENT. n 



marked ; we see this in the Box (Buxus sempervirens), and notably in th^ leaf of the Ginkgo 

 (Salisburia adiantifolia, fig. 41), where the foliage has the appearance of being cleft down the 

 centre — a form botanically known as bifid. You will see that, ornamentally, this gives quite a 

 new character. There is, perhaps, no more beautiful kind of leaf form for designing purposes 

 than such as the Syc2Lmor:Q( Acer pseudoplatanus, fig. 36^ afford^ a type of, where we get a central 

 prominent mass, and other similar forms given off laterally. The radiating character, and the 

 subordination of the various masses to each other, are very valuable points (if the reader covers 

 up the two apparently insignificant basal lobes, he will see at once how the whole form suffers), 

 while the toothed edge imparts further pleasant variety to the outline. 



Botanically and physiologically the leaf is full of interest ; but the points of greatest 

 practical value to the designer, and therefore those that alone now concern us, are the following : — ■ 

 1 — Its position on the stem. 2 — Its general form as a mass. 3 — The character of the outline. 

 4 — The venation. 5 — The texture. We propose, then, to take up briefly these points for con- 

 sideration. 



A leaf may be either stalked, as that of the Apple ( Pyrus Malus) ; or stalkless, as in the 

 Pimpernel ( Anagallis arvensis). The leaf may entirely surround the stem, as in the perfoliate 

 Honeysuckle ( Lonicera Caprifolium), or its basal lobes, instead of thus uniting, may be continued 

 down the sides of the stem. In this case the leaf is decurrent ; we see instances of it in the 

 Comfrey (Symphytum officinale), and in several of the thistles. 



Leaves may occur singly at intervals on the stalk, when they will ordinarily be found to grow 

 in a spiral. In the Oak (Quercus robur), for instance, only one leaf is given off at one level ; and if 

 any one of these leaves be brought immediately opposite to the eye, the next one above it will be 

 found to be at an angle with us, while the next still further recedes, and it is not until we get to 

 the sixth leaf that we find it exactly over number one ; we shall find that seven will be over two, 

 eight over three, and so on — five leaves thus completing one cycle. We see this special arrange- 

 ment also in the Pear (Pyrus communis). In some cases the spiral is much more elaborate ; while, 

 on the contrary, in the Meadow Saffron (Colchicum autumnale) three leaves suffice to complete one 

 revolution — number four then coming over number one, number five coming over two, &c. ; the 

 simplest form of all is that termed alternate, as in the Ivy (Hedera Helix), where the. third leaf 

 comes over the first, the fourth over the second, and so on. Sometimes leaves grow in pairs, as 

 in the Ground Ivy (Nepeta glechoma, fig. 155). In this case the pairs of leaves ordinarily alternate 

 in their direction, the second pair being at right angles to the first, and number three returning to 

 the direction taken by number one ; a cross-like form is thus given to the foliage when seen in plan. 

 In some plants, however, all the pairs are placed in the same direction, so that instead of being a 

 cross form, when looking down on the growth, the top pair will conceal all those beneath it. We see 

 a good instance of this in the opposite-leaved Pond-weed (Potamogeton densus). In the Globulea 

 obvallata the successive pairs of opposite leaves are arranged in a spiral, the second pair not being 

 in a parallel line with the first, nor at right angles with it, as we see it in the great majority of 

 plants, but at a slight angle, so that it is not until we arrive at the seventh pair that we find any 

 of its leaves coming directly over those from whence we started in our investigation. When leaves 

 are not opposite or alternate, they are said to be verticillate or whorled, except in the Pines and 

 Firs, where the leaves, being gathered together in small bundles, are said to be fascicled (Lat. 

 fasciculus, a little bundle). The number of leaves in a whorl varies considerably, thus in the 

 Anacharis alsinastrum, or American Water Weed, now so rapidly spreading throughout our Eng- 

 lish water-courses, the leaves are in threes : in the cross-leaved Heath (Erica Tetralix) in fours ; 

 while in the Goose-grass (Galium aparine) the whorl is composed of many more parts. It is a 

 law of universal force in vegetable organography that the greater the number of parts the less 

 regular they are ; thus the opposite or two-leaved arrangements are most constant ; but, when three 

 leaves compose the ring, a variation from the normal number is occasionally met with, while the 

 fluctuation is most marked when the normal number is greater. In one hundred whorls of the 

 Goose-grass that we counted to test this, thirteen were composed of six leaves, thirty-eight had 

 seven, forty-one had eight, while the remaining eight had nine. In one hundred whorls of the 

 great Hedge Hedstraw (Galium Mullugo) the variation was equally striking. Fourteen examples 

 had six leaves to the whorl, eighteen of the whorls had seven leaves, fifty had eight leaves, 

 seventeen had rings of nine leaves, while one whorl had ten. 



The general form of the leaf, as it would tell as a mass in the design, is artistically a very 

 important feature. We have already described some of the simpler forms. Leaves are either 

 simple (figs. 55, 67, 91, 123, 169), or compound (figs. 125, 152, 173, 181); simple, when the 

 divisions do not pass down to the central line : compound, when they do. Compound leaves are 

 of two very marked types, either, in the first case, where the parts all radiate from one centre — 

 the Horse Chestnut leaf (figs. 311, 326) is a good example of this; or, secondly, where these 



