126 



CASSELL'S POPULAE GABDEXIXG. 



PROPAGATION 



Br W. Watson. 



Li Hum. 



Lithosperinum. 

 Mentha. 

 Packypkytum. 

 Pelargonium. 



Pkyllag-atkis. 

 Pinguicula. 

 Sempervivuoj. 

 Watercress. 



PROPAGATION BY LEAVES. 



UXDEB certain conditions buds are formed on 

 the leaves, the roots, or the flower-stems of a 

 large number of plants ; such buds being called 

 adventitious, to distinguish them from the stem or 

 normal buds, that are found present on all plants, 

 and which are borne in the axils of the leaves. It 

 is supposed that the leaves of a very large propor- 

 tion of plants possess this power to develop extra- 

 ordinary buds, and that their failing to do so when 

 tested by the gardener is due to improper treatment 

 rather than to absolute impotence in the leaf itself. 

 It is, however, only in a few cases that leaf-cuttings 

 are resorted to for purposes of propagation, such 

 plants as Begonia, Gloxinia, Echeveria, and a few 

 others, of more or less succulent nature, being the 

 only ones for the increase of which leaf- cuttings are 

 employed. Xumerous other plants have proved 

 capable of propagation by this means, some of them 

 being not at all succulent-leaved, while, on the other 

 hand, plants of excessive succulence have proved 

 unable to form buds when tested in the same way. 

 In some cases where leaf- cuttings have been tried, 

 roots were freely developed, but no bud was formed. 

 Fieus elastica, Camellias, and Soya carnosa may be 

 mentioned as plants whose leaves root freely but do 

 not develop buds, although left in the propagating- 

 house for several years. Lindley states that the 

 leaves of Eoses strike freely, but will not form buds, 

 a peculiarity which, along with the above, is sup- 

 posed to belong to the nature of species, and is not 

 easily explained. 



Where it is desirable that a new plant should be 

 propagated as abundantly and rapidly as possible, it 

 will be found often advantageous to place the leaves 

 that are removed from stem-cuttings in the propa- 

 gating-frame, and treat as advised below. That 

 success might come when least expected may be seen 

 by the following list, which comprises plants capable 

 of propagation by leaf-cuttings. To any one ac- 

 quainted with the nature of these plants, it will be 

 apparent that no rule can be laid down for the 

 guidance of the cultivator, either when based on the 

 texture of the leaves or the nature of the plants. 



List of plants that may be propagated by means 

 of leaves or portions of leaves : — 



iEsckynantkus. 



Begonia. 



Bertolonia. 



Bryopkyjliim. 



Cardamine. 



Cepkaeks. 



Citrus. 



Cliantkus. 



Eckeveria. 



Fritillaria. 



Pucksia. 



Gasteria. 



Gesnera. 



Gloxinia. 



Haworthia. 



Hippeastrum, 



Hoya. 



Hyacintkus. 



In this list only those plants are included whose 

 leaves have proved able to form buds capable of 

 developing into plants, and it will be understood 

 that a large number of plants might be added to the 

 above if their leaves were tested. This method of 

 propagation is only rarely resorted to ; a fact which 

 accounts for the smallness of the number of plants 

 known to be amenable to it. 



Turning now to the plants that are usually in- 

 creased from cuttings made of leaves, a word may be 

 said on the treatment such leaves require, and the 

 best time of year for the operation. Gloxinias may 

 be dealt with at all times of the year when leaves 

 are obtainable, the most favourable period being 

 autumn. Well-matured leaves should be selected, 

 avoiding those in which the yellowness of decay has 

 appeared. The leaf-stalk may be severed at any 

 point, it being unnecessary to secure them with 

 a heel or portion of the stem. The blade may then 

 be divided longitudinally, so that a large leaf would 

 form about half a dozen cuttings. It is, however, 

 better when the blade is cut into sections, each 

 section having a portion of the midrib attached to 

 its base. Some prefer severing the midrib into 

 about a dozen pieces, leaving the blade intact. In 

 this way a plant is obtained from each portion of the 

 midrib, bulbils being developed on the lower end of 

 each. Where the latter plan is adopted the whole 

 leaf must be pegged on to a pan of sandy soil. If 

 the leaf is divided up into smaller pieces, cutting- 

 pots may be used, filling the pots half full of drain- 

 age, and the other half with a light sandy soil. Into 

 this the cuttings must be placed, obliquely, so that 

 whilst held firmly in the soil their bases are only a 

 little below the surface. A hot-bed or close frame 

 in a propagating-house will be the most suitable 

 place for the cuttings till rooted. In a small moist 

 stove, a position on a shelf near the glass would 

 answer equally well for Gloxinia cuttings. 



Bertolonias may be increased from healthy ripened 

 leaves, which, if the midrib be nicked in several 

 places, and the whole leaf then pegged on to a pot 

 of very sandy peat, soon form roots and tiny tubers 

 at every incision, if placed in a moist propagating- 

 frame. For these plants autumn is the most suitable 

 season, the leaves at that time being more vigorous 

 than at any other. B. Van Soutteana is easily in- 

 creased from leaf-cuttings ; B. Marmorata and one 

 or two others sometimes produce good seed, from 

 which abundance of plants may be obtained. 



Gasterias, Haworthias, Echeverias, Sempervivums, 

 and such-like succulents, are easily propagated from 



