iv OUTLINES OF BOTANY. 



26. A bulb is a stock of a shape approaching to globular, usually rather conical above and 

 flattened underneath, in which the bud or buds are concealed, or nearly so, uiider scales. These 

 scales are the more or less thickened bases of the decayed leaves of the preceding year, or of the 

 undeveloped leaves of the future year, or of both. Bulbs are annual or perennial, usually under- 

 ground or close to the ground, but occasionally buds In the axils of the upper leaves become 

 transformed into bulbs. Bulbs are said to be scaly when their scales are thick and loosely unbri- 

 cated, tunicated when the scales are thinner, broader, and closely rolled round each other in 

 concentric layers. 



27. A corm is a tuberous rootstock, usually annual, shaped like a bulb, but in which the bud or 

 buds are not covered by scales, or of which the scales are very thin and membranous. 



§ 4. The Stem. 



28. Steins 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 applied to any 

 rhizomes or roots which spread horizontally. 



tufted or caspitose, when very short, close, and many together from the same stock. 



29. Weak climbing stems are said to twine, when they support themselves by winding spirally 

 ound 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 aboveground, 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 comprised 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 ; gemiiiate, temate, fascicled, oi fasciculate, ■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 an axillary 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 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 ; distichous, when regularly arranged one above another in two opposite rows, one on each side 

 of the stem ; tristicJums, when in three rows, etc. (92). 



scattered, when irregularly arranged round the stem ; frequently, however, botanists apply 

 the term alternate to all branches or leaves that are neither opposite nor whorled. 



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



33. Branches are dichotomous, when several times forked, the two branches of each fork 

 being nearly equal ; trichotomous, when there are three nearly equal branches at each division 

 instead of two ; but when the middle branch is evidently the principal one, the stem is usually 

 said to have two opposite branches ; umbellate, when divided in the same manner into several 

 nearly equal branches proceeding from the same point. If however the central branch is larger 

 than the two or more lateral ones, the stem is said to have opposite or whorled branches, as the 

 case may be. 



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

 Monoootyledonous plants. 



§ 5. Tlie Leaves. 



35. The ordinary or perfect leaf consists of a flat blade or lamina, usually green, and more 

 or less horizontal, attached to the stem by a stalk called a footstalk or petiole. When the form 

 or dimensions of a leaf are spoken of, it is generally the blade that is meant, without the petiole 

 or stalk. 



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

 stem or other organ, is called its base, the opposite end is its apex or summit, excepting sometimes 

 in the case of anther-cells (115). 



