Morphology 



flowers open successively from the bottom towards the 

 top, whereas in corymb, umbel, and capitulum they 

 open successively from the circumference towards the 

 centre, or centripetally. In 

 either case, however, the order 

 of opening of flowers is acro- 

 petalous. In an umbel or cap- 

 itulum the apex of the peduncle 

 from which the pedicels or the 

 widened head arise is usually 

 clothed with a whorl of bracts 

 known as an involucre. 

 Racemes, spikes, spadices, and 

 umbels may be simple or com- 

 pound, according as the floral 

 axis is unbranched or branched. 

 Compound racemes are very 

 common, hence they are desig- 

 nated by the special name of 

 PANICLE. In capitulum the 

 flowers are usually closely 

 crowded together and very 

 small, and are therefore known 

 as FLORETS or little flowers. 

 All the florets may be similar 

 in shape, or, as is more com- 

 mon, the florets of the circum- 

 ference known as ray-florets 

 differ in shape from the florets 

 of the centre known as disk- 

 florets, the ray-florets being 

 the disk-florets tubular. The 

 head of a capitulum is often provided with small scaly 

 or slightly coloured bracts known as palea, which 

 embrace the florets. When the palea are absent the 



Figr. 71. — Kacliu 

 {Colocasia anliguoricm) 



a. Female flowers $. S, Male 

 flowers $. c. Appendix. s, 

 Spathe. 



usually ligulate, and 



