THE LIFE-HISTORY OF PLANTS. 



9i 



this mode of propagation one or more buds are sepa- 

 i-ated from the parent stock and form now plants. 

 "Parting the root," then, is only another way of 

 taking cuttings. 



Another form of root-stock is exemplified by what 

 gaideuers call " creeping roots," as in the common 

 Bindweed (Convolvulus) or the Couch-grass [Triti- 

 cum repens). "Why these are not -strictly roots will 

 be understood from what has already been said. 

 Such forms of rhizome are an unmitigated nuisance 

 to the gardener and farmer. There are, however, in- 

 stances where this mode 

 of growth is very advan- 

 tageous, as on sandy sea- 

 shores or dunes, where 

 these so-called creeping 

 roots render inestimable 

 service in partiallj- fixing 

 the sand and preventing 

 its dispei'seil over the 

 neighbouring country. 

 By their means, planting 

 with Broom, 

 Furze, and 

 other plants, 

 to act as 

 nm'ses for 

 valuable 

 Pines, be- 

 comes possi- 

 ble, and thus 

 what were 

 once barren 

 wastes may 

 be converted 

 into most pro- 

 fitable land. 

 This affords 

 an excellent 



iUustration of the value that accrues from the study 

 of the mode of growth of the conunonest weeds. We 

 are aU to apt to despise these weeds rather than to 

 utilise them and turn them to advantage, as we 

 might readily do. 



Root-stocks, like bulbs, afford chaiacteristio ex- 

 amples of the " indefinite " and " definite " modes 

 of growth (see VoL I., page 298). In the common 

 Solomon's Seal (Polygonatum muUiflorum) we have 

 a long, thick, horizontal root-stock, terminated by 

 a stalk, which ascends to bear leaves and flowers, 

 and which is the real termination of the stem. 

 The horizontal growth is carried on by a bud 

 formed at the side near the tip of the root-stock, and 

 which bud itself ends in an inflorescence the follow- 

 ing season. In other cases the growth is " indefi- 

 nite" because the root-stock ends in a leaf-bud. 



rie 37.— Eoot-stock of Solomon-s Seal (Polsgonotum multi^iorum), giving off roots 

 from the under soxface and shoots from the upper aide. 



which continues the horizontal growth below 

 gi'onnd, the leaves and flowers being borne on 

 axillary buds produced from the side of the root- 

 stock, and thrust up into the light and air — e.g., 

 Primrose, Couch-grass. It must be remembered 

 that the terms definite and indefinite in these cases 

 refer to the order and direction of growth, and not to 

 time, and this is the more important to be borne in 

 mind in that most of these plants with root-stocks are 

 what are called '.'herbaceous perennials." Their 

 growth in a particular direction may be checked, or 

 it may not be, but in 

 either case the duration 

 is limited. The young 

 shoots die ' down in 

 winter, not, however, 

 before provision has 

 been made for the future 

 by the development of 

 new buds from the flanks 

 or end of the stock, 

 which new buds wiU re- 

 main dor- 

 mant through 

 the winter, 

 to start in- 

 to renewed 

 growth the 

 following 

 season, as 

 we have seen 

 to be the 

 case with 

 bulbs. While 

 growth is 

 thus provided 

 for at or near 

 one end of 

 the stock, it 

 generally happens that decay and death of the older 

 portions at the opposite end occur, and thus it hap- 

 pens that by the onwai-d march of the new and the 

 decay of the old parts, the plant actually changes its 

 position in course of time. 



The conditions of growth above alluded to furnish 

 the explanation of the directions so generally given 

 to " part or divide the roots," or to transplant every 

 two or three years certain kinds of herbaceous per- 

 ennials. 



Tlie Root. — Coming now to the consideration of 

 the root proper as an organ of absorption— " feeding- 

 roots " as the gardener appropriately terms them— 

 we may pass over as unimportant in the present 

 connection aU the varied forms of roots described in 

 books. We may ignore in practice the distinction 



