ELEMENTAKY BOTANY. V 



§ 4. The Stem. 



28. Stems are 



erect, when they ascend perpendicularly from the root or stock ; twiggy or virgate, 

 when at the same time they are slender, stiff, and scarcely branched. 



sarmentose, when the branches of a woody stem are long and weak, although 

 scarcely climbing. 



decumbent or ascending, when they spread horizontally, or nearly so, at the base, 

 and then turn upwards and become erect. 



procumbent, when they spread along the ground the whole or the greater portion 

 of their length ; diffuse, when at the same time very much and rather loosely branched. 



prostrate, when they lie still closer to the ground. 



creeping, when they emit roots at their nodes. This term is also frequently ap- 

 plied to any rhizomes or roots which spread horizontally. 



tufted or ccespitose, when very short, close, and many together from the same 

 stock. ' 



29. Weak climbing stems are said to twine, when they support themselves by wind- 

 ing spirally round any object ; such stems are also called voluble. When they simply 

 climb without twining, they support themselves by their leaves, or by special clasping 

 organs called tendrils (169), or sometimes, like the Ivy, by small root-like excrescences. 



30. Suckers are young plants formed at the end of creeping, underground rootstocks. 

 Scions, runners, and stolons, or stoles, are names given to young plants formed at the 

 end or at the nodes (31) of branches or stocks creeping wholly or partially above- 

 ground, or sometimes to the creeping stocks themselves. 



31. A node is a point of the stem or its branches at which one or more leaves, 

 branches, or leaf-buds (16) are given off. An internode is the portion of the stem com- 

 prised between two nodes. 



32. Branches or leaves are 



opposite, when two proceed from the same node on opposite sides of the stem. 



whorled or verticillate (in a whorl or verticil), when several proceed from the 

 same node, arranged regularly round the stem ; geminate, ternate, fascicled, or fascicu- 

 late when two, three, or more proceed from the same node on the same side of the 

 stem. A tuft of fasciculate leaves is usually in fact a leafy branch, so short that the 

 leaves appear to proceed all from the same point. 



alternate, when one only proceeds from each node, one on one side and the next 

 above or below, though usually not in the same vertical line. 



hJi ecus . 3ate > whe n opposite, but each pair placed at right-angles to the next pair above 

 or below it ; distichous, when regularly arranged one above another in two opposite 

 ^ws, one on each side of the stem ; tristichous, when in three rows, etc. (92). 



scattered, when irregularly arranged round the stem ; frequently, however, bota- 

 wh leH Ply the term alternate t0 a11 branches or leaves that are neither opposite nor 



<»q* e S W ^' Wnen al * 8tart from or are turned t0 one 8ide of tlie 8tem * 

 eacbV , ranches are dichotomous, when several times forked, the two branches of 

 at * i j. bein S nearly equal ; trichotomous, when there are three nearly equal branches 



each division instead of two ; but when the middle branch is evidently the prmci- 

 vid °r ' tll ° 8tem is us u a Hy said to have two opposite branches ; umbellate, when di- 

 ttoing "VJf Same man uer into several nearly equal branches proceeding from the same 

 stem' • however the central branch is larger than the two or more luteral ones, the 



is said to have opposite or whorled branches, as the case may be. 

 rvtlwT" *7" culm is a m »ne sometimes given to the stem of Grasses, Sedges, and some 

 oUier.Monocotyledonous plants. 



§ 5. The Leaves. 

 and D m T,?e 0rdin *»7 or perfect Leaf consists of a flat blade or lamina, usually green, 

 wLnT °, F le83 horizontal, attached to the stem by a stalk called a footstalk or petiole. 

 mean? , f ° rm or dimensions of a leaf are spoken of, it is generally the blade that is 



3€ tT lth0ut the **** ^ stalk. 

 D - A he end by which a leaf, a part of the flower, a seed, or any other organ, is 



32 



