SECT. II 



PHANEROGAMIA 



489 



members of a flower as shown in the floral diagram. Denoting the calyx by K, 

 the corolla by C (if the perianth forms a perigone it is denoted by P), the androe- 

 cium by A, and the gynaeceum by G, the number of members in each case is 

 placed after the latter. Thus the floral formula of the monocotyledonous flower 

 represented in Fig. 441 would be, P 3 + 3, A 3 + 3, G 3. When there is a large 

 number of members in a whorl the symbol oo is used denoting that tlie number is 

 large or indefinite. Such a formula may be further made to denote the cohesion 

 of the members of a whorl by enclosing the proper number within brackets, and by 



placing a horizontal line 

 below or above the number 

 of the carpels the superior or 

 inferior position of the ovary 

 is expressed. By placing 

 an arrow before the formula 

 the dorsiventrality of the 

 flower may be indicated, 

 and by varying the direction 

 of the arrow it can be made 

 clear whether the dorsi- 

 ventrality ismedian, oblique, 

 or transverse. The formula 

 for the Lily given above and 



Fig. 440. — Flowers of, A, Scutellaria ulpina, medianly zygo- 

 morphic (dorsiventral) ; B, Aesculushippocastanum, obliquely 

 zygomorphic (rlorsiventral) ; C, Corydalis lutea, transversely 

 zygomorphic (dorsiventral) ; d, bracts. 



Fifi. 441. — Diagram of a penta- 

 cyclie flower {LiUum). 



for a number of other flowers would thus take the following forms :— 



Lily. P3 + 3, A3 + 3, G (3). 

 Buttercup. K5, C5, A^, G^. 

 Laburnum. |K5, C 5, A (5 + 5), G 1. 



Hemlock. K5, C5, A5, G(2). 

 Artemisia. KO, C (5), A (5), G (2). 



Inflorescence. — In many Angiosperms the single flowers are borne in large 

 numbers on special branch systems which diifer in a number of respects from the 

 vegetative branch systems, and are termed inflorescences. In inflorescences, as 

 in the vegetative region (cf. p. 20), branches usually arise only from the leaf-axils, 

 the subtending leaf being termed a bract. Leaves borne on the axis of the flower 

 itself are known as bkacteoles. Bracts and bracteoles may be classed together 

 as BiiACTEAL LEAVES (Fig. 442). The median plane passes through the axis and 



