GLOSSARY OF 



BOTANICAL TEEMS 



USED IN PLANT DESCRIPTION. 



THE ROOT. 

 Origin. 



Primary : when originating directly from the lower end of 

 the radicle of the embryo (Fig. 1). Such a root is usually 

 (but not always) single, and may send out lateral fibres 

 as it grows ; such fibres or branches are included in the 

 primary root. 



Annuals and biennials, and many trees, have, as a rule, 

 only primary roots. 



Secondary : when originating from any other part of the 

 nlaut than the end of the radicle, as from the sides of 

 stems (J^'ig. 2), from tubers, rootstocks, bulbs, cuttings, 

 etc. 



Perennial herbs, creeping plants, and most shrubs, jiro- 

 duce such roots abundantly. 



Form. 



Tap : having a main central axis, distinctly larger than any 

 of the branches (Fig. 3). 



Fibrous : made up of many similar parts wuiiout a disiincr 

 central axis (Fig. 4). 



A tap-root is 



(a) Ccnical, when it gradually tapers from a broad top 

 (Fig. 5). 



(b) Sjmidle-shaped or fusiform, when thickest in the 

 middle (Fig. 6). 



(c) Turnip-shaped or napiform, when nearly globular 

 with an abruptly tapering base (Fig. 7). 



Fibrous roots are 



(a) Of coarse threads, as in Buttercup. 



(b) Of fine threads, as in any common grass. 



(c) Fascicled or clustered or tuberous, when each of 

 the iibi-es has become a fleshy mass, as in Peonj^ (Fig. 8). 



(In description the Variety may follow the Form on the 

 same lino ; for example, Form; Tap, conical.) 



Colour. 



In many plants the colour of the root is characteristic, and 

 should always be given in the description. 



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