110 The Biology of the Lowland Plants. 
Chapter II. The Biology of the Lowland Plants, 
1. Growth-Forms. 
Here except when otherwise stated, only the 514 species of spermophytes 
and pteridophytes which are confined to the lowlands and lower hills are dealt 
with, since their biology should reflect more closely the ecological conditions _ 
than would that of the total lowlandglower-hill flora embracing, as it does, 
many species common on the high mountains. 
a. Trees. 
There are 77 species of trees of which ı3 are tall (24 m and upwards), 
ıı medium (15s—ı8 m) and 53 small (6—ı2 m or even less) while at least 30 
occur also at times in the adult-form as shrubs. Nearly all the trees are ever- 
green, only 8 species being deciduous or semi-deciduous. 
The following are the growth-forms and the number of species in each 
— Tuft-tree 9, of which 6 are.tree ferns and 2 branching‘); canopy-tree 33; 
bushy-tree 27; araliad 5; tree-composite 2; leafless-juncoid 1”). In 27 species, 
there is a juvenile form quite distinct from that of the adult and, in most 
cases, persisting for many years. The two most striking cases are where the _ 
juvenile is a divaricating shrub (7 species) or where there is an erect unbran- 
ched, or almost unbranched stem furnished with leaves much longer and nar- 
 rower than those of the adult (9 species‘). 
 Regarding the tree-trunks, those of no less than 40 species rarely exceed 
30cm in diam., and in some cases are much less; those of ı5 vary from about 
30 to 60 cm; those of 8 reach above go cm nt finally, 14 species have 
 specially massive trunks more than ı m‘) in diam. (Plate XVIII, Fig. 24.) In some 
2 A IR cases are recorded of branching i in the palm eg mergie, sapida). For ie = 3 
Stevensoni. 
8) This i is BERRT E an extreme in the ee cases op Pseudopanax er assifolium ( 
 P.ferox. In the first-named, there is a primary stage with stalked, coarsely-toothed, home 
or en lanceolate leaves cuneate at the base and some 6mm to 5 cm long which 
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