278 BOTANY 



Multiplication by Multicellular Vegetative Bodies (Budding) 



often consists merely in the separation of lateral shoots, or in a division 

 of a single plant into several. In this way the lateral shoots of the 

 Water Fern, Azolla, through the death and disruption of the older 

 parts of the parent axis, become separated from one another and con- 

 tinue their growth as independent plants ; similarly, separate plants 

 originate from the vegetative body of the Duckweed (Lemna). 



Multiplication by stolons, rhizomes, and tubers results in a similar 

 formation of independently existing plants. As may be seen in the 

 Strawberry, Potato, Ranunculus repens, etc., the shoots produced from 

 many of the axillary buds of the widely outstretched stolons take 

 root and form new plants. In cases where the runners themselves 

 eventually die, the parent plant becomes finally surrounded by a colony 

 of entirely independent plants. 



Instead of forming runners, the single tuber may divide (Corydalk 

 solida), and in this way give rise to two, four, or more new tubers. 

 New bulbs are produced in the leaf-axils of the bud-scales of bulbs, 

 while brood buds (bulbils, gemmae) are frequently developed on aerial 

 vegetative organs. 



Bulbils are found on the inflorescence in the place of the flowers in many species 

 of Allium, in the grass Poa bulbifera, and also in Polygonum mviparum. In 

 Lilium buTbiferum; Dentaria bulbifera, etc., the bulbs in the axils of the leaves 

 are specially constructed with a view to detachment from the parent plant. The 

 swollen leaves contain reserve food material, and frequently develop roots before 

 falling from the plant. In Ranunculus Ficaria the roots of the axillary buds are 

 full of reserve food material, and resemble grains of corn. "When the plant dies the 

 bulbils remain on the ground, and have given rise to the fable of showers of grain. 

 Bulbils or gemmae are met with also among the Mosses, Liverworts, and Charas. 

 The winter buds of many water-plants (Bydrocliaris, Utricularia, Potamogeton 

 crispus, Lemna, etc. ) have a peculiar biological significance. They are formed in 

 the autumn, and sink to the bottom of the water ; in the succeeding spring they 

 rise to the surface and form new plants. 



In addition to the instances just cited, in which the vegetative reproductive 

 bodies take their origin from points where lateral shoots are normally formed, they 

 may also appear in places where no shoots are normally developed. Thus the 

 adventitious formations often found on leaves, particularly on the leaf- blades, 

 serve the purpose of reproduction. Just as the leaves of the Begonia, after they 

 have been cut off, are able to give rise to new plants, in other cases the leaves 

 possess this power while still growing on the parent plant. Some Ferns afford 

 specially characteristic examples of this (Asplenium decussatum, A. Fabianum, 

 A. bulbiferum, A. viviparum) ; adventitious buds are produced on their laminae, 

 which develop into small rooted plants, which then fall off and complete 

 their development (Fig." 215). The adventitious buds of Cystopteris bulbifera 

 take the form of bulbils with small swollen leaves. Adventitious plantlets are 

 frequently formed also on the leaves of Oardaminc pratcnsis, and Cardamine amara 

 manifests a similar tendency. One of the best known examples of such adventi- 

 tious formations is afforded by the leaves of the tropical Bryophyllum, in whose 

 marginal indentations the brood plantlets develop in great numbers. Gemmae are 

 abundantly produced on the thallus of many ITepaticae (Marchantia, Lunularia), 



