6o PLANT LIFE. 



even leaves. The buds are not of very great interest ; 

 the winter buds of water plants, the bulbils of 

 Polygonum viviparum, those of Saxifraga granulata and 

 of some Garlics {^Allium vineale, A. Scorodoprasum 

 A. oleraceuni^ etc.) are the most important. The Saxi- 

 frage ''''bulbils'' are small, round, white bodies, which 

 can be easily seen at the base of the stem ; they are 

 produced instead of ordinary branches ; those of the 

 garlic are about the size of a pea. They are solid 

 and fleshy, and occupy the position of the flower stalks 

 which they replace. 



Leaves are seldom used for non-sexual colonisation. 

 The common Ladies' Smock {Cardaniine pratensis)^ how- 

 ever, often forms roots and a bud on its lowest or basal 

 leaves, and these may produce a new plant. Some 

 species of Sedum throw ofl' both the leaf and the 

 small bud within it, and this " off-shoot " forms a new 

 individual. The Begonia is regularly propagated by 

 dividing, and sowing parts of its leaves. 



On the other hand, leaves are frequently employed to 

 store up food material over the winter. The Woodsorrel, 

 for instance, has a very thin, delicate creeping stem, along 

 which little triangular fleshy bodies may be seen. These 

 are the bases of old leaves and contain a reserve of food. 

 The bulbs of the onion, and all the varieties of Allium, 

 such as leeks, garlic, shallot, etc., as well as most of the 

 Lily order, also store up their food in the fleshy base 

 of the leaves. Generally a protecting outer coat is 

 formed from the withered and dry base of the outermost 

 leaf, and this covers and protects the rest ; but, in some 

 cases, each fleshy scale ends above in a hardened tip, and 

 these hard extremities form a protecting mosaic, covering 

 the surface of the bulb. Two very well-known ferns, 

 the " Mother of Thousands " and the " Walking Fern " use 



