INTUODIJCTION. V 



§ 4, The Stem. 



28. Stems are 



erects when tliey ascend perpendicnlarlj from the root or stock ; hoiggy or virgate^ 

 when !it the same thne they are slender, stiff, and scarcely branched. 



sarmentose^ when the branches oi a -woodi^ stem arc lone and weak, althoueh 

 scarcely climbing. a > b 



deciimherit 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 then- 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 ccBspiiose, when yery short, close, and many together from the same 

 stock. 



. ^"'- y^ ^^k climbing stems are said to tmne^ when they support themselves hj wind- 

 ing spu^ally round any object; such stems are also called voluble. When they simply 

 chmb without twining, they support themselves by their leaver, or by special clasping 

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



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

 ^cio7is, runners, and stolons, or stoles, are names given to joung plants fonned at the 

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

 ground, or someiimes to tlie 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 inter node is the portion of the stem 

 comprised between two nodes. 



32. Branches ur leaves are 



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



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

 same node, arraTiged regularly round t!ie stem ; geminate, ternatc, fascicled, or fascicu- 

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

 stem. A tuft of fasciculate leaves is usually iu fact an axillaiy leafy branch, so short 

 that tlie leaves appear to proceed all from the same point. 



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

 above or below on the opposite side of the stem. 



decussate, when opposite, but each pair placed at right-angles to the next pair above 

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

 rows, one on each side of tlie stem ; trisiichous, when in three rows, etc. (92). 



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

 nists apply the term alternate to all branches or leaves that are neither opposite nor 

 wdiorled, 



secund, when all start from or are turned to one side of the stem. 



33. Branches are dichoiomous, when several times forked, the two branches of 

 each fork being nearly equal ,- trichotomous, when tljcre are three nearly equal branches 

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

 pal one, the stem is usually said to have two opposite branehes ; nmbellate, when di- 

 vided in the same manner into several nearly equal brandies proceedhig from the same 

 point.^ If however the central branch iri larger than the two or more lateral ones, the 

 ^tcm is said to have opposite or whorled branches, as ihe case may be. 



34. A culm is a name sometimes given to the stem of Grasses, Sedges, and some 

 other Mouocotyledonous plants. 



F 



§ 5. The Leaves^ 



35. The ordinary or perfect Leaf consists of a flat blade or lamina, usnally green, 

 and more or less horizontal, attached to the stem by a stalk called a footstalk or petwle, 

 >^ieu the form or dimensions of a leaf are spoken of, it is generally the bl:H]e tJiat is 

 nieant, without the petiole or stalk, , 



36. The end by which a leaf, a part of the flower, a seed, or any other organ, is 



