IVY 31 



is a root-climber. The climbing roots press into all the in- 

 equalities of the surface, against which they grow and become so 

 firmly attached to this that when the shoot is pulled off they 

 remain attached to the support. 



The shoot of the Ivy consists of a stem with elongated inter- 

 nodes bearing one leaf at each node. The stem retains its green 

 colour for a long time, but the older branches with their 

 covering of cork are brown. The creeping or climbing shoots 

 lie close to the substratum, and their leaves are so arranged as to 

 display the leaf-blades to the light without overshadowing one 

 another. The leaves have long leaf-stalks, and the simple blade 

 is of a triangular shape divided into three or five lobes. Main 

 veins supplying these lobes diverge from the base of the leaf. When 

 a plant has attained a considerable height, other shoots are 

 developed which do not cling closely to the supporting surface, 

 but stand out from this. These branches bear the leaves on all 

 sides of the stem, and the leaves are oval and pointed, not 

 lobed like those on the climbing shoots. The existence of two 

 types of shoot, a climbing and a freely projecting, is character- 

 istic of many climbing plants, but the Ivy is the best example in 

 our flora. The inflorescences are borne on the freely projecting 

 shoots. 



All the projecting branches end in inflorescences, and others 

 <re developed in the axils of the small bracts borne on the stalk 

 >f each main inflorescence. The end of the stalk is somewhat 



ilated, and from it in the axils of small bracts a number of long 

 stalked flowers spring, forming an umbel (Plate). These flowers 



o not open until October or November, and, though not very 

 conspicuous, and greenish-yellow in colour, are visited by numerous 

 insects in search of the abundant nectar. The flower-stalk widens 

 above into the almost globular, inferior ovary marked by five 

 proj ecting ribs. These ribs run down from the five small triangular 

 teeth which represent the sepals. Alternating with these are 

 five relatively large greenish-yellow petals which form the most 

 conspicuous part of the flower. The centre of the flower is occu- 

 pied by the large, yellowish, nectar-secreting disc, from the middle 

 of which rises the short style. The five stamens which alternate 

 with the petals stand at the edge of the disc. All these parts can 



