Flowers and their Parts 



149 



General Method. 



Usually indefinite 



Definite . 



Mixed 



Kinds of Clusters. 

 . Raceme — Corymb : more or less flat- 

 topped ; Ornithogalum. 

 Panicle : branched stalks ; 

 Grasses. 

 Umbel — Simple : Hydrocotyle (definite.) 



Compound : Daucns. 

 Capitulum (or head) — Composites, Pro- 

 tea. 

 . Cyme — 2-sided : dichasium, Spergula, 

 Crassula. 

 i-sided : cincinnus, Lohostemon, 

 Heliotrope. 

 . Cymose — (Heads and panicles) — Leonotis, 

 Olive. 



Bracts. — In examining flower arrangements, the flowers 

 are usually found protected by one or more leaf-like bodies, 

 green or coloured, which 

 may have been mistaken 

 for the calyx. In G/a- 

 diolus^ Antholyza, and 

 their relatives, this mis- 

 take is often made, but 

 you will find that in these 

 flowers the sepals are like 

 petals, and are borne at 

 the top of the ovary. 



Leaves in whose axils 

 flower-buds instead of 

 leaf-buds arise, are termed 

 bracts. They are gener- 

 ally smaller than leaves, 

 but sometimes much 

 larger and more showy 

 than the flowers, as in 

 Protea, Poinsettia, and Hc^manthus. 



Fig. 145.— Flower and fruit of the Olive, 

 showing a definite or cymose panicle 

 (see p. 147)- 



When several bracts 

 surround a head of flowers, as in Protea, the Barberton Daisy, 

 and others of their tribe, they form an involucre. 



When a bract is large and sheaths the inflorescence, as in 

 Arum, it is called a spathe. Bracts which enclose the flowers 

 of grasses and sedges are called pales and glumes. 



