228 PROP A GA TION B Y LEA VES. 



Propagating by Bulb-bearing Leaves. The leaves of malaxis paludosa 

 bear little bulbs at their extremities ; several sorts of allium originate 

 bulbs in the axils of the bracts ; and in some ferns, such as asplenium 

 bulbiferum, and Woodwardia radicans, bulbs are found at the extre- 

 mities of the leaves, which when these touch the soil, grow, throw 

 down roots, and produce young plants. 



Propagation by Leaves. 



This mode of propagation is of considerable antiquity. It is said by 

 Agricola ('L'Agriculteur Parfait, &c.,' ed. 1732) to be the invention 

 of Frederick, a celebrated gardener at Augsburg, and to have been 

 first described by Mirandola, in his ' Manuale di Giardinieri,' published 

 in 1652. Subsequent experiments by C. Bonnet, of Geneva; Noisette, 

 Thouin, Neuman, and Pepin, of Paris ; Knight, Herbert, and others, 

 in England and Germany, have proved that there is probably no 

 class of plants which might not be propagated by leaves. It has been 

 tried with success with cryptogainous plants, with endogens and exo- 

 gens ; with the popular divisions of ligneous and herbaceous plants, 

 annuals, biennials, and perennials, and with the leaves of bulbous 

 plants and palms. 



The conditions generally required for rooting leaves are, that the 

 leaf be nearly full grown ; that it be taken off with the petiole entire ; 

 that the petiole be inserted from an eighth to half an inch, according 

 to its length, thickness, and texture, in sandy loam, or in pure sand on 

 a stratum of rich soil ; and that both the soil and the atmosphere be 

 kept uniformly moist, and at a higher temperature than is required for 

 rooted plants of the same species. The leaves cf such succulents as 

 cacalia, crassula, cotyledon, kalankoe, portulaca, sedum, sempervivum, 

 cactus, gloxinias, begonias, and similar plants, root when laid on the 

 surface of soil, with the upper side to the light, the soil and atmo- 

 sphere being kept sufficiently close, moist, and warm. The first change 

 that takes place is the formation of a callosity at the base of the petiole; 

 after which, at the end of a period which varies greatly in different 

 plants, roots are produced, and eventually, at an equally varying period, 

 a bud from which a leafy axis is developed. 



Rooting Portions of Leaves. In 1839, M. Neuman, of the Paris Garden, 

 saw the theophrasta latifolia (Clavija ornata, D. Don) growing so well 

 from cuttings of leaves, that he conceived the idea of cutting several of 

 them in two, and treating them in the same manner as entire leaves. 

 Accordingly, he cut a leaf in two, and planted both parts in the same pot, 

 treating them exactly alike. In about three months, the lower half of 

 the leaf had made roots, but the upper half had none ; though, some 

 time afterwards, when it became necessary to separate the cuttings, M. 

 Neuman found that the upper part of the leaf had also made roots, but 

 that these roots were much shorter than those of the lower half. The 

 rooting of the two halves of a leaf of the theophrasta, so hard and dry 

 as every one knows these leaves to be, appearing to him an interesting 

 circumstance, he continued to pay attention to them for six months. 



