IV INTRODUCTION TO BOTANY. 



26. Suclrrs arc yonnc: plants formed at the end of crccpirif^, nndorpT-onnd 

 rootstocks. 



27. Scions, rNinicrs, and ftoIo)is, or stoks, are names given to young plants 

 fonned at the end, or at the vodes (28) of branches or stocks, creeping 

 wholly or partially above-ground, and sometimes to the creeping stocks 

 themselves. 



28. A »ode is a definite point on the stem or on a branch, at which one 

 or more leaves are given off, and an internode is the portion of a stem com- 

 prised between two nodes. The nodes are pervious when the pith passes 

 continiiousl}' tlu'oiigh them, and closed or impervious when it is inteiTupted 

 by partitions, as in grasses, etc. 



29. Liafbuds are small conical bodies, usually covered with scales, and 

 found in the axils (33) of leaves of the previous season or of earlier growth ; 

 when occurring in other positions, as they sometimes do, they are con- 

 sidered adventitious or iiregular. They contain the germs of future 

 branches. 



30. Branches (or leaves) are, 



opposite, when two proceed from the same node at opposite sides of 



the stem; whorlcd ovverficillate, when several proceed from the 



same node, arranged regularly, like the spokes of a wheel, 



round the stem. 

 geminate, or in pairs, when two proceed from the same node, 



at the same side of the stem. 

 ternate, in threes, when three spring from one point. 

 fascicled, when several spring from the same or nearly the same 



apparent point. 

 alternate, when one only proceeds from each node, one on one side, 



and the next above or below on the opposite side of the stem. 

 dec^issate, when opposite, but each pair placed at right angles to the 



one next above or below it ; 

 distichous, when in two ranks ; tristichous, in three, etc. 

 scattered, when placed irregularly round the stem ; but this is often 



confounded with alternate. 

 secund, when all start from or turn towards one side of the stem, 



like the teeth of a rake. 



31. Branches are, 



forked, when they di-vnde at the end into two or more equal 



branches ; 

 dichotomoics, when each 2-pronged fork is figain divided, and this 



mode of division several times repeated ; 

 trichotomotis, when the forks are 3 -pronged, and this repeated ; 

 umbellate, when divided at the apex into several branches, and the 



central one not larger than the rest. 



32. The straw-like stems of grasses and some other endogens are 



often called culms. 



§ 5. The Leaves. 



33. Leaves are expansions which issue laterally from the stem and 

 branches, and usually bear a leafbud (29) in their axil, i.e. in the angle 

 formed by the leaf and the branch. 



34. An ordinary leaf consists of an expanded, usually flat blade or 

 lamina, joined to the stem by a footstalk or petiole. The extremity of the 

 lamina next the stem is the base, the opposite extremity the apex., and a 

 line separating the upper and under sm-faces, the margin. 



35. Leaves are, 



sessile, when the blade rests on the stem without the intervention 

 of a petiole. 



