678 



BOTANY 



PART II 



Frangulinae. The increasingly tetracyclic floral construction, the formation of a 



disc in the flower, the forma- 

 tion of secretory reservoirs.'and 

 the 



canals, and the one -seeded 

 loculi of the fruit are all points 

 of resemblance to the Umbelli- 

 florae. 



Family 1. Cornaceae. 

 Cornus mas, the Cornelian 

 Cherry (Fig. 721), expands its 

 umbels of tetramerous yellow 

 flowers before the leaves appear. 

 Each umbel is subtended by 

 four bracts. The inflorescences 

 for the succeeding year are 

 already present in the axils 

 of the leaves by the time the 

 fruit is ripe. In Britain two 

 species occur : 0. sanguinea, 

 the Dogwood, and C. suecica, 

 an arctic and alpine plant 

 which reaches its southern 

 limit in Germany. 



Family 2. Araliaceae. In 

 Britain the only representa- 

 tive of the family is the Ivy 

 (Hedera Helix) ( 27 ), a root- 

 climber. The elliptical pointed 



FIG. 721. Cornui mas ( nat. size). 1, Flowering twig. 

 Twig with fruits. 3, Flower seen from above. A, Flower 

 in longitudinal section. (3, k, enlarged.) 



FIG. 722. Umbelliferae. Floral 

 diagram (Stter). (After NOLL.) 



FIG. 723. Fruits of Umbelliferae in cross section. 1, Foenv-nlinn 

 capillaceum. 2, Pimpinella anisum. 3, Conlum maculatum. 

 It, Coriandrum sativum (It modified after a figure by CRUDE). 



leaf form appears on the orthotropous shoots of older plants, which in late 



