18 AUSTRALIAN BOTANY. 



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LESSON IV. 

 STEMS. 



The stem is that part of a plant which bears, or has 

 formerly borne, leaves. Stems do not necessarily grow 

 above the ground, some plants having underground stems. 

 The majority, however, are above the surface. Stems 

 support the foliage and flowers, supplying them with 

 moisture from the roots. The stem springs from the bud 

 or plumule, as shown in Lesson I. Stems may be divided 

 into two kinds, herbaceous and woody. The word ' herba- 

 ceous ' is variously applied. It signifies plants producing 

 annual stems from perennial or long-lived roots. It also 

 means thin, green, and cellular (having cells), and is 

 generally used to indicate soft-wooded plants, such as the 

 potato, garden sage, perennial Phlox, Dahlia, etc. 



The following are the principal kinds of stems : — 

 Erect Stems, such as those of ironbark, messmate, stringy 

 bark, giant-gum, red-gum, blue-gum, or l fever-tree,' 

 jarrah, myrtle-tree of Victoria, and others, generally 

 termed trunks. 

 Climbing Stems, as in the grape vine, pea, etc., have 

 tendrils}- or fine shoots. In other plants, such as 

 the ivy, trumpet flower (Tecoma radieans), they have 

 aerial roots serving the same purpose. In a third 

 class, of which the native virgin's bower {Clematis 

 aristata) is an example, the leaf-stalks closely resemble 



1 ' Tendrils (cirrhi) are usually abortive petioles, or abortive 

 peduncles, or sometimes abortive ends of branches.' — Bentham. 



