SEEDLINGS 



337 



and a similar type of foliage is found in Podocarpus, which is 

 allied to the Yew. Podocarpus is the most important genus of 

 Conifers in the Southern Hemisphere, comprising some sixty 

 species, of which several furnish valuable timber. 



In spite of the considerable diversity in the mature structure, 

 the seedlings of most Conifers exhibit great uniformity, the 

 young stem bearing ordinary needle-leaves for some little distance 

 above the cotyledonary node (Fig. 195). The dwarf-shoots of 



B 



FIG. 194.. Arbor Vitae (Thuja). A, Branch with ripe female cones (about 

 natural size) . B, Small part of a branch enlarged to show the leaf- 

 arrangement. 



Pinus and other Abietineae, as well as the scale-like leaves found 

 in the Cypress, etc., only appear at a later stage and as a 

 secondary development. By appropriate means the juvenile 

 foliage can be made to persist, even in the adult condition, as 

 in some cultivated varieties of Thuja and Cupressus (the Retino- 

 spora of nurserymen). Even the deciduous habit of the Larch 

 appears as a secondary acquisition, since in the seedling the 

 leaves persist for some time. It is not always that the varied 

 specialisation which a group has undergone, in evolving from a 

 22 



