244 



THE DICTIONARY OF GARDENING, 



Layering continued. 



be placed together, and the branch allowed to enter at 

 the bottom. The pot must be afterwards filled up with 

 soil, and made secure, by some means, from falling apart 

 or shifting about. A covering of moss over the pot 

 tends to keep the soil moist, by preventing an undue 

 evaporation, resulting from its suspension in the air. 

 This is sometimes called the Chinese method of Layering, 

 presumably on account of it being more generally adopted 

 in China. 



Some plants Cordylines, for instance will form roots 

 readily in a moist stove, if an incision is made in a firm 

 part of the stem, and some moss tied round, without soil. 

 The moss must be kept syringed, and the old roots of the 

 plant somewhat dry, until new ones are formed at the place 

 desired. 



Layers should, in all cases, be allowed to become well 

 rooted before being detached. 



LAYIA (named in honour of Thomas Lay, naturalist 

 in Beechey's voyage). SYNS. Eriopappus, Madaroglossa. 

 Including Callichroa, Calliglossa, and Oxyura. ORD. 

 Composites. A genus comprising about a dozen species 

 of hardy, pubescent or hirsute, often glandular, mostly 

 annual herbs, natives of North America. Flower-heads 

 heterogamous, pedunculate ; rays yellow or white ; disk 

 yellow; achenes pilose or rarely glabrous. Leaves alter- 

 nate, narrow, entire, or the lower ones rarely all pinna- 

 tifid. The species, not many of which have been intro- 

 duced, thrive in any ordinary garden soil. Propagation 

 may be effected by seeds, sown on a hotbed. 



L. Calliglossa (Calliglossa). This differs from L. chrysanthemoides 

 principally in having a pappus of usually several (ten to eighteen) 

 unequal, rigid, subulate awns. California. SYN. Oxyura, chrysan- 

 themoides (under which name it is figured in B. B. 1850). 



L. chrysanthemoides (Chrysanthemum-like), jl. -heads solitary, 

 on sub-clavate peduncles, tomentose ; ray -florets yellow at base, 

 paler at apex, broad-oblong, tnlobed ; pappus none. August 

 and September. I., lower ones pinnatifid; uppermost ones quite 

 entire ; all slightly scabrous on the margin. h, lift. California, 

 1834. 



L. platyglossa (broad-tongued). This is the correct name of the 

 plant described in this work as Callichroa, platyglossa. (B. M. 

 3719 ; S. B. F. G. ser. ii. 373.) 



LEADWORT. See Plumbago. 



LEAF. A Leaf is an expansion of the cellular tissue 

 of the stem, traversed by fibro-vascular bundles. The 

 use of Leaves is to afford a large surface for exposing 

 to the action of sunlight and heat the food absorbed by 

 the plant, and thus cause assimilation ; they also provide 

 for evaporation, and absorb the carbonic acid of the air. 

 The various terms employed in describing the shape, 

 duration, and insertion, &c., of leaves will be found in 

 their proper places in this work. 



LEAP BUDS. See Buds, Leaf. 



LEAFLET. One of the divisions of a compound 

 leaf. 



LEAF MINERS. Many plants are liable to have 

 their leaves mined by the larvse of minute insects, which 

 may belong to various groups Beetles (Orchestes Fagi in 

 Beech-leaves, &c.), Sawfiies (species of Fenusa, Ac.), 

 Lepidoptera (species of Lithocolletis, &c.), and Diptera 

 (species of Phyiomyza, &c.). In general, the affected 

 plants seem to suffer little harm from the existence of the 

 mines, unless these are very numerous. This is fortunate, 

 as the only remedy is to crush the larvae in the leaf 

 between the finger and thumb a remedy not suitable for 

 extensive application. See also Celery Fly, Holly-leaf 

 Fly, and Parsnip Fly. 



LEAF MOULD. Leaves, when thoroughly decayed, 

 so that they readily separate into small particles, constitute 

 what is termed Leaf Mould, a valuable manure in many 

 instances, especially on heavy soils, and one of the most 

 important ingredients for the soil used in the successful 

 cultivation of the majority of pot plants. If of good 

 quality, and free from injurious fungoid growths, it may 



Leaf Mould continued. 



be used freely, particularly with tender seedlings and 

 cuttings of soft-wooded subjects. The production of roots, 

 in young plants of this description, is induced and ac- 

 celerated with more certainty by planting in the material 

 under notice than by the use of any other. The quality 

 of Leaf Mould depends very materially on the sort of 

 leaves composing it, and in the manner of preparation 

 adopted. The best leaves are those collected from a wood, 

 or other place, where the principal trees are Beech and 

 Oak, and where their leaves fall over a large surface 

 each year, and naturally decay slowly until those beneath 

 the surface become changed into a light mould. In many 

 instances, such Leaf Mould cannot be obtained, on ac- 

 count of the necessary removal of the leaves to preserve 

 tidiness; but, on the other hand, its importance and ad- 

 ditional value over that artificially prepared is insuffi- 

 ciently recognised in many places where quantities might 

 be collected in woods. Leaf Mould of good quality may 

 be used to the extent of about one-third in composts for 

 Azaleas, greenhouse Rhododendrons, and many fine-rooted 

 hard-wooded plants of this description. It may, with 

 advantage, be freely incorporated along with peat in the 

 preparation of beds for nearly all Ericaceous plants 

 outside. Further, nothing is better suited for improving 

 flower-beds, or for adding to soil of any description for 

 placing round trees, shrubs, or plants, whose roots it is 

 desired to encourage. If leaves have to be gathered 

 into a heap for Leaf Mould, a place should be selected 

 where they may be spread rather thinly, so as to avoid 

 any excessive heating by fermentation. The whole should 

 be turned over occasionally, so as to expose all parts in 

 turn to the influence of the weather and air. Where air 

 cannot reach leaves that are of a somewhat hard, dry 

 texture, their decay is exceedingly slow, unless there are 

 other substances intermixed to hasten decomposition. 

 Water may be applied artificially for the purpose, but 

 it never has the same effect as rain ; and if a large heap 

 is made, this latter cannot penetrate far into the interior. 

 Leaves should be collected free from sticks, if possible, 

 as these are liable to encourage fungoid growths, which, 

 finding a suitable medium for increasing in the Leaf 

 Mould, will, in due course, render it useless for plant 

 cultivation. The time taken in reducing leaves to a 

 mould or fine soil depends greatly on the amount of 

 turning over, and other attention devoted to the pre- 

 paration. Much may be done in one year, or even less; 

 but the quality is usually better if a longer time than 

 this is allowed. 



LEAF PROPAGATION. The propagation of 

 plants by their Leaves is a method of rapid increase 

 adopted with great advantage in the case of those which 

 succeed. An incision made in any firm part of the midrib, 

 as well as the petiole, will, in certain instances, induce the 

 production of a young plant. Ornamental-leaved Begonias, 

 Gesneras, Gloxinias, and several succulent plants, are 

 familiar examples of subjects largely increased by Leaf 

 Propagation. Doubtless, many other sorts of plants 

 might be similarly perpetuated, if their leaves remained 

 fresh for a sufficiently long time to enable a callus to form. 

 Leaves which are nearly fully matured, but still not too old, 

 are preferable for propagating purposes ; they will not suc- 

 ceed at all if very young. Merely pegging them on light 

 soil, or covering very lightly, for preserving moisture, is 

 generally sufficient, with the protection of a close frame or 

 bell glass. Succulents, increased by Leaf Propagation, should 

 have their fleshy leaves simply laid on or very lightly 

 pressed into sand, and be kept nearly dry on a shelf 

 until a small bulbil-like plant forms at the end of each, 

 where it has been detached. The propagation of plants 

 by leaves is generally limited to the petiole or ribbed 

 portion. Bryophyllum calycinum is, however, an excep- 

 tion, as young ones spring, in this case, from the 

 notches on the margin of the leaf. 



