STEMS. 21 



If above ground, it is root-shaped, or knotted ; ascending ; 

 creeping ; articulated ; leafless, succulent, and deformed ; or 

 leafy. 



If it bears the flowers, proceeding immediately from the soil or 

 near it, it is a scape. 



22. The stem, in most plants, rises vertically in the air, but 

 sometimes it wants strength to sustain itself, and rests drooping 

 on the surface of the ground, to which it often attaches itself by 

 roots (stems of this kind are named repent or creeping), or they 

 sustain themselves upon some other more robust plant, as is seen 

 in the climbing plants, &c. It is observed that the latter often 

 wind themselves spirally round whatever supports them; they are 

 then called twining or voluble ; and it is worthy of note, that the 

 direction according to which different individuals of the same 

 species wind themselves, never varies; in some, such as the 

 haricot or bean, and bind-weed, it is from right to left ; in others, 

 such as the honeysuckle and hop, it is constantly from left to 

 right. 



23. While young, stems are always of a soft consistence and 

 similar to grass ; they often remain in this state, and live but a 

 year ; they are then called herbaceous stems. In other instances 

 they acquire more or less hardness, their interior is transformed 

 into wood, and they live out of the ground many years : in this 

 case they are called ligneous stems. 



24. When the stem, although it be persistent, remains watery 

 and more or less soft, it takes the name of fleshy stem. 



25. We generally apply the name of shrub to those plants 

 with a ligneous stem which branch at their base, and do not 

 much exceed a man in height, such as the rose or lilac ; and we 

 give the name of tree to those with a ligneous (woody) stem that 

 branch only at the superior part, and rise to a considerable 

 height. The branches are only divisions of the trunk which di- 

 verge more or less from it, and are again subdivided in their turn ; 

 upon their arrangement depends the general form of the plant ; 

 sometimes they stand up, which gives the tree a pyramidal form ; 

 sometimes they are spread out, and at others they are pendent or 

 hanging. 



26. Stems of certain plants present at intervals knots or enlarge- 



22. What is meant by a creeping stem ? What is meant by twining or 

 voluble stems ? What is especially remarkable in these stems? 



23. What is an herbaceous stem 1 What is a ligneous stem ? 



24. What is a fleshy stem ? 



25. What is a shrub? How does a tree differ from a shrub? 



26. What is a culm ? 



