Low. — On Haastia pulvinaris. 151 



pact branches, with their round, flat tops, are all of the 

 same height, and are all so closely packed together " that 

 the point of a pencil," or even of a pin, cannot be thrust 

 down between them (fig I.). The older branches reach a 

 diameter of ■!■ in.— |-in., but as they are coated down to the 

 ground with old leaves they appear to have a much greater 

 diameter. The stem is of a brownish colour, with bark. 



The branch system is a polychasium (fig. II.). The main 

 axis gives rise either to one or two lateral branches which 

 keep pace with it, and they themselves send out one or two 

 lateral branches, which likewise reach the same height. In 

 this way no one branch exceeds the rest in height, and the 

 surface is flattened. As all the branches are short, the result 

 is an extremely compact mass. 



In the leaves of Haastia lies its great peculiarity 

 (fig. XI., A, B). They are, as Hooker describes them, 

 " patent, with dilated, rounded tips, margins recurved towards 

 the tip." The leaf is sessile, with a fairly broad base, the 

 lower part of the leaf membranous and colourless, while the 

 recurved, upper portion is thick and of a bright-green. But it 

 is in the presence of the characteristic " wool " that the leaf 

 is, perhaps, most peculiar. This consists of vast numbers of 

 long and slender hairs, which grow from all parts of its sur- 

 face, except on the lower part of its inner surface, which 

 part closely embraces the stem. The recurved tip is the 

 most densely covered with wool. 



Arrangement of leaves : The divergence is two-fifths. 

 Although the leaves are so closely packed together on the 

 stem and cannot be distinguished from each other when the 

 branch is intact, yet the divergence two-fifths appears to be 

 kept very regular throughout. 



The root is of about the same thickness as the stem, is 

 much branched, and has a brown, barky appearance. The 

 tap-root is extremely rigid, is clothed in bark, and is several 

 feet in length. 



3. Minute Anatomy. 



Stem. 



The structure of the young stem is marked by a circular or 

 elliptic resin-passage in the cortex, opposite each vascular 

 bundle (fig. III.), surrounded by a secreting layer of cells, 

 smaller than those of the cortex, and sometimes havinsf 

 granular contents. The vascular bundles have the ordinary 

 structure of open, collateral bundles, and are, at this stage, 

 quite distinct and separated by ground parenchyma, although 

 cambium is beginning to appear between them. The epider- 

 mal tissue is very shghtly cuticularised, and underneath it is 



