ORGANS OF REPRODUCTION. 189 



Fig. SI I. Fig. 372. Fig. 37 S. 



Fig. 371. Flowering stalk of the Pimpernel 

 (Anagallis an-ensis). b. Solitary flowers 



arising from the axil of the bracts, a 



Fig. 372. Flower of Marsh-Mallow (AUhcea 

 officinalis) surrounded by an epi-calyx or 

 involucre Fig. 373. Flower of Straw- 

 berry {Fragnria vesca), surrounded by an 

 epi-calyx or involucre. 



from the ordinarj leaves not only by 



their position, but also by differences 



of colour, outline, and other particulars. 



Sometimes when the bracts are situated 



in a whorl immediately below the calyx 



/ //l\\\\ ^^ °^^^^^ covering of the flower, it is dif- 



( / / f j nj ficult to determine whether they should 



V I PJ ]j be considered as a part of the calyx 



V I j^ or as true bracts ; thus in the Mallow 



\/|P tribe {fig. 372), many of the Pink tribe, 



I> and Kose tribe {fig. 373), we have a 



circle of leafy organs placed just below 



the calyx, to which the term of epicaJyx has been given by 



many botanists, but which properly comes under the denomina"- 



tion of involucre (page 190). 



Almost all inflorescences are furnished with bracts of some 

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

 them do not develop flower-buds, just in the same manner as 

 it occasionally happens that the 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 Clarj (Salvia Horminum) and common Pine- apple there 

 are a number of bracts without flower-buds placed at the apex 

 of the inflorescence. Bracts from which flower-buds do not 

 arise are called empty. When bracts are absent altogether, as in 

 the plants of the natural order Cruciferre, and commonly in the 

 Boraginacete, such plants are said to be ebracteated. 



Bracts follow the same law of arrangement as true leaves, 

 being opposite, alternate, or whorled, &c., in different species! 

 The bracts of the Pine-apple fruit (fig. 706, 2) and those of 



