Floivers and tlieir Parts 



147 



strictly one or the other arrangement, but the definite and 

 indefinite are often mixed. The flower cluster of the Olive is 

 a panicle, but the separate branches have the flowers arranged 

 in cyraose clusters. In Leonotis each separate flower cluster 

 is definite, but the younger clusters are at the top. The 

 terminal umbels of Wild Carrot, which are the first to open, 

 are indefinite. Younger umbels tip the branches which come 

 from the axils of lower leaves, the youngest being lowermost 



Fig. 143.— Compound umbel of Bubon. 1 From Edmonds and Marloth's 

 Elementary Botany for South Africa ''.) 



on the stem. In other umbels of this order the central flowers 

 open first. 



The simple umbel oi Nerbie (Fig. 142) is definite, as they 

 are in Asclepias, Hydrocotyle, Sparmaniiia. jThe youngest 

 flowers in the Sunflower family are always at the centre but in 

 Scabiosa the heads are cymose. These definite umbels may 

 consist of condensed clusters of cymes as in Agapaiithtis. 



The garden Foxglove sometimes, instead of rearing stately 

 racemes of flowers, has a large terminal flower which looks like 

 several joined into one (peloria). This stops the growth of 



10 * 



