OUTLINES OF BOTANY. XXI 



globular or spherical, when corresponding to orbicular in a fiat sur- 

 face. Round applies to both. 



turbinate, when shaped like a top. 



conical, when tapering upwards ; obconical, when tapering downwards ; 

 if in both cases a transverse section shows a circle. 



pyramidal, when tapering upwards ; obpyramidal, when tapering down- 

 wards ; if in both cases a transverse section shows a triangle or polygon. 



fusiform, or spindle-shaped, when tapering at both ends ; cylindrical, 

 when not tapering at either end ; if in both cases the transverse section 

 shows a circle, or sometimes irrespective of the transverse shape. 



terete, when the transverse section is not angular ; trigonous, trique- 

 trous, if the transverse section shows a triangle, irrespective in both cases 

 of longitudinal form. 



compressed, when more or less flattened laterally; depressed, when 

 more or le£S flattened vertically, or at any rate at the top ; obcompressed (in 

 the achenes of Composites), when flattened from front to back. 



articulate or jointed, if at any period of their growth (usually when 

 fully formed and approaching their decay, or in the case of fruits when 

 quite ripe) they separate, without tearing, into two or more pieces placed 

 end to end. The joints where they separate are called articulations, each 

 separate piece an article. The name of joint is, in common language, given 

 both to the articulation and the article, but more especially to the former. 

 Some modern botanists, however, propose to restrict it to the article, giving 

 the name of joining to the articulation. 



didymous, when slightly two-lobed, with rounded obtuse lobes. 



moniliform, or beaded, when much contracted at regular intervals, but 

 not separating spontaneously into articles. 



55. In their consistence Leaves or other organs are 



fleshy, when thick and soft; succulent is generally used in the same 

 sense, but implies the presence of more juice. 



coriaceous, when firm and dry, or very tough, of the consistence of 

 leather. 



membranous, when thin and not stiff. 



scarious or scariose, when very thin, more or less transparent and not 

 green, yet rather stiff. 



56. The terms applied botanically to the consistence of solids are those 

 in general use in common language. 



57. The mode in which unexpanded leaves are disposed in the leaf-bud 

 is called their vernation or prcsfoliation ; it varies considerably, and techni- 

 cal terms have been proposed to express some of its varieties, but it has 

 been hitherto rarely noticed in Descriptive Botany. 



§ 6. Scales, Bracts and Stipules. 



58. Scales (Squama) are leaves very much reduced in size, usually 

 sessile, seldom green or capable of performing the respiratory functions of 

 leaves. In other words, they are organs resembling leaves in their position 

 on the plant, but differing in size, colour, texture, and functions. They 

 are most frequent on the stock of perennial plants, or at the base of annual 

 branches, especially on the buds of future shoots, when they serve appa- 

 rently to protect the dormant living germ from the rigour of winter. In 

 the latter case they are usually short, broad, close together, and more or 

 less imbricated, that is, overlapping each o^her like the tiles of a roof. It is 



