102 ■ MANUAL OF BOTANY 



and woody ; in the Hop (fig. 216) they are membranous ; in 

 certain plants of the Araoefe and Enphorbiacese, coloured ; in 

 the flower-heads of the Compositse, scaly ; and other modifica- 

 tions also occur. 



Sometimes when a number of bracts are situated in a whorl 

 immediately below the calyx, it is difficult to determine whether 

 they should be considered as a part of the calyx or as true bracts : 

 thus, in most flowers of the Mallow order [fig- 193), we have 

 a circle of leafy organs placed just below the calyx, to which the 

 term epicalyx has been given. 



Almost all inflorescences are furnished with bracts of some 

 kmd or other ; it frequently happens, however, that some of 

 the bracts do not develop axillary flower-buds, just in the same 

 manner as it occasionally happens that leaves do not produce 

 leaf-buds in their axils. In some cases the non-development of 

 flower-buds in the axil of bracts appears to arise simply from 

 accidental causes ; but in others it occurs as a regular law ; thus, 

 in the Purple Clary {Salvia Horminiini) and the common Pine- 

 apple {fig. 167), there are a number of bracts without flower- 

 buds placed at the apex of the inflorescence. Such bracts are 

 called emptij. When bracts are absent altogether, as is usually 

 the case in the plants of the natural order CruciferEE, and those 

 of the Boraginacese, such plants are termed ehracteate ; when 

 bracts are present, the inflorescence is said to be bracteate. 



Arrangement and Duration of Bracts. —Bracts follow the 

 same laws of arrangement as true leaves, being opposite, alter- 

 nate, or whorled, in different plants. The bracts of the Pineapple- 

 fruit {fig. 167) show in a marked manner a spiral arrangement. 



Bracts xnvy in their duration : when they fall immediately 

 after the flower-bud expands, they are said to be deciduous ; 

 when they remain long united to the floral axis, they a.re per- 

 sistent. In some plants they persist and constitute a part even 

 of the fruit : in the Hazel-nut and Filbert they form the ciqjule 

 (fig. 199), in the Acorn they constitute the cup (fig. 198) ; and in 

 the Hop (fig. 216), in the Fir-cones {figs. 168 and 244), and Pine- 

 apple (fig. 167), they persist as membranous, woody, fleshy, or 

 scaly appendages. 



Varieties of Bracts. — Bracts have received special names 

 according to their arrangement and other characters. Thus 

 the bracts of that kind of mflorescence called an amentum or 

 catkin, as seen in the WiUow (fig. 214), Oak, Hazel (fig. 195), 

 Birch, and other plants, are usually of a scaly nature, and are 

 termed squamice or scales ; or the bracts are described as 



