LAY 



LEA 



Greenhouse herbaceous perennials, from New 

 Holland. Divisions ; loam and peat ; require a 

 cold pit or cool greenhouse during winter. 

 L. gra'cilis (slender). . Purple, white. June. 



1824. 

 grandiflo'ra (large-flowered). White, brown. 



LAYER. The following excellent com- 

 bination of practice and science is from 

 Dr. Lindley's " Theory of Horticulture:" 

 A layer is a branch bent into the earth, 

 and half cut through at the bend, the 

 free portion of the wound being called " a 

 tongue." It is, in fact, a cutting only 

 partially separated from its parent. The 

 object of the gardener is to induce the 

 layer to emit roots into the earth at the 

 tongue. With this 1 view he twists the 

 shoot half round, so as to injure the 

 wood- vessels ; he heads it back, so that 

 only a bud or two appears above ground, 

 and when much nicety is requisite, he 

 places a handful of silver-sand round the 

 tongued part; then, pressing the earth 

 down with his foot, so as to secure the 

 layer, he leaves it without farther care. 

 The intention of both tonguing and 

 twisting is to prevent the return of sap 

 from the layer into the main stem, while 

 a small quantity is allowed to rise out of 

 Ae latter into the former ; the effect of 

 ihis being to compel the returning sap to 

 organize itself externally as roots, instead 

 of passing downwards below the bark as 

 wood. The bending back is to assist in 

 this object by preventing the expenditure 

 of sap in the formation, or rather, com- 

 pletion of leaves, and the silver-sand is 

 to secure the drainage so necessary to 

 cuttings. 



In most cases this is sufficient ; but it 

 must be obvious, that the exact manner 

 in which the layering is effected is un- 

 important, and that it may be varied 

 according to circumstances. Thus, Mr. 

 James Munro describes a successful 

 method of layering brittle - branched 

 plants by simply slitting the shoot at the 

 bend, and inserting a stone at that place; 

 (Gardeners Magazine, ix. 302;) and Mr. 

 Knight found that, in cases of difficult 

 rooting, the process is facilitated by ring- 

 ing the shoot just below the tongue about 

 Midsummer, when the leaves upon the 

 layers had acquired their full growth ; 

 (Hart. Trans, i. 256 ;) by which means 

 he prevented the passage of the return- 

 ing sap further downwards than the 

 point intended for the emission of roots. 

 It will sometimes happen that a branch 

 of a plant cannot be conveniently bent 



downwards into the earth ; in such cases, 

 . the earth may be ele- 



\ ' r vated to the branch by 

 \ f various contrivances, as is 

 \iv / commonly done by the 

 Chinese. When this is 

 done, no other care is 

 necessary than that re- 

 quired for layers, except 

 to keep the earth sur- 

 rounding the branch stea- 

 dily moist. See figure. 



LAYING-IN is a gar- 

 dener's term for training 

 the branches of espaliers 

 and wall-trees. Laying -in-by-the-heels is 

 his mode of describing a plant's having 

 its roots roughly buried in the soil for 

 some temporary purpose. 



LAZY-BEDS are beds dug for the growth 

 of potatoes, the sets being then placed in 

 rows on the surface, and covered by the 

 soil dug out of narrow, deep alleys be- 

 tween the beds. 



LEADWOET. Plumba'go. 

 LEAF-MOULD. This is formed of leaves 

 kept moist and in a heap, frequently 

 turned over, until completely decayed, 

 and reduced to a dark brown, moist 

 powder. It usually takes two years to 

 complete this process. An excess of 

 water delays the decaying, and either 

 lime or gas ammoniacal liquor promotes 

 it; but then few potted plants are bene- 

 fited by any such excess of either of these 

 additions. 



LEATHEBWOOD. Di'rca. 

 LEAVES are highly vascular organs, 

 in -which are performed some of the most 

 important functions of a plant. They 

 are very general, but not absolutely ne- 

 cessary organs, since the branches some- 

 times perform their offices. Such plants, 

 however, as naturally possess them, are 

 destroyed, or greatly injured, by being 

 deprived of them. 



The duration of a leaf is, in general, for 

 a year only, though in some plants they 

 survive for twice or thrice that period. 

 These organs are generally of a green 

 colour. Light seems to have a powerful 

 influence in causing this, since, if kept 

 in the dark, they become of a pale 

 yellow, or even white hue, unless un- 

 combined hydrogen is present, in which 

 case they retain their verdure though 

 light be absent. Hence their blanching 

 would seem to arise from their being 

 unable to obtain this gas iincler ordinary 



