SCALE-LEAVES, FOLIAGE-LEAVES, FLORAL-LEAVES. 641 



first bud (plumule) situated above the hypocotyl (cf. fig. 2). In this case the floral 

 leaves, collected together to form the flower, follow directly above the foliage- 

 leaves on the same shoot. Such a flower is called terminal. Much more frequently 

 the flowering axis or peduncle is inserted laterally on an older shoot, and origin- 

 ates close above a leaf, called a subtending leaf; here we speak of lateral flowers. 

 Usually several flowers are grouped in a definite way, and the term inflorescence 

 (inflorescentia) has been introduced to distinguish these groupings. The subtending 

 leaf (folium fulcrans) either agrees in general character with the lower foliage- 

 leaves, and is then said to be " leaf-like ", or it differs in shape and size as well as in 

 colouring, and is then spoken as a bract (bractea). 



These leaves, differing from foliage-leaves, always have a special relation to the 

 processes of fertilization; and are therefore to be reckoned with the floral-leaves. 

 Frequently a whole inflorescence is surrounded and supported by a single enormous 

 bract, and in such inflorescences, which are very characteristic of palms and aroids, 

 the bracts at the base of the individual flower-stalks are usually undeveloped. This 

 large common bract is called a spathe (spatha). The Climbing Palm (Desmoncus) 

 illustrated in fig. 157 3 , has such a spathe beset with prickles. It sometimes hap- 

 pens that some of the flowers of the inflorescence do not develop, and that then 

 bracts are to be seen without flowers. If such " empty bracts " are found crowded 

 together at the base of the inflorescence arranged at one level, or are there grouped 

 in very close spiral revolutions, we speak of an involucre (involucrum). Some- 

 times they are to be seen at the apex of the whole inflorescence, the group forming 

 what we may call a crest. Minute, stiff, dry bracts, without chlorophyll, in the 

 centre of thickly crowded inflorescences are called palece (palece). 



In flowers we distinguish perianth-leaves, stamens, and carpels. The perianth- 

 leaves, are arranged either spirally or in whorls. The former arrangement is 

 observed most noticeably in the cacti, of which several species, including Cereus, 

 Mamillaria, and the remarkable hedgehog-like JEchinocactus capped by its flower, 

 are illustrated at vol. II., p. 787. In the many-membered perianth inclosing the 

 flowers of this plant more than a hundred perianth -leaves are so arranged at 

 small vertical intervals along a spiral line that the smallest stand lowest, the 

 largest uppermost, not unlike the leaves of the involucral cup around the capitulum 

 of a composite. This spiral arrangement, however, is rare, at least in such a 

 striking form. Much more frequently the perianth -leaves form two successive 

 whorls. If the lower whorl consists of green leaves, which agree in texture and in 

 general appearance with foliage-leaves, while the upper is composed of more delicate 

 leaf -structures displaying all possible colours except green, the lower is called 

 calyx, and the upper the corolla. If all these perianth -leaves are shaped and 

 coloured very much alike, so that there is no marked contrast between the whorls, 

 we then speak of a perigone (perigonium). This may be either green like a calyx, 



or coloured like a corolla. 



The stamens (stamina), the "attire" of the older botanists, are, like the pei 

 anth-leaves, usually whorled, or, more rarely, arranged in spirals. Each stamen 



VOL. I. 



