MONOCOTYLEDONS AND DICOTYLEDONS 



267 





formula, and one that appears among the highest Sym- 

 petalffi. 



The name of the family is suggested by the character- 

 istic inflorescence, which is also of advanced type. The 

 flowers are reduced in 

 size and massed in flat- 

 topped clusters called 

 umMs (Figs. 252, A, 253). 

 The branches of the clus- 

 ter arise in cycles from 

 the axis like the braces 

 of an umbrella. As a re- 

 sult of the close approxi- 

 mation of the flowers the 

 sepals are much reduced 

 in size and often obsolete 

 (Fig. 252, C). 



The Umbellifers are 

 mainly perennial herbs of 

 the north temperate re- 

 gions, forming a very dis- 

 tinct family, and contain- 

 ing the following familiar 

 forms : carrot (Daiiciis) 

 (Fig. 252), parsnip {Pasfi- 

 naca), hemlock {Conmm) 

 (Fig. 253), pepper-and- 

 salt [Erigenia), caraway 

 {Carum), fennel {Fcenic- 

 uhim), coriander {Cori- 

 andriim), celery (JjJi- 

 um), parsley {Petroseli- 

 num), etc. Allied to the 

 Umbellifers are the Ara- 

 lias {Araliacem), and the 

 Dogwoods [Cornacew). 



Fig. 253. Hemlock {Conium), an Umtellifer, 

 showing the umbels, with the principal 

 rays rising from a cycle of bracts iinvo- 

 lucre), and each bearing at its summit a 

 secondary umbel with its cycle of second- 

 ary bracts iinvolucel). — After Schimpeb. 



