Kirk. — On the New Zealand Species of Phyllocladiis. 379 



True leaves are only produced in the young state ; they disappear before 

 the plant attains its third year ; rudimentary scale-like leaves, from the 

 axils of which the broad foliaceous organs are produced, are developed on 

 the branches, but soon fall off. The broad fern-like foliaceous expansions, 

 which take the place of true leaves, are by some termed "cladodia," by 

 others " phyllodia," according to the X3oint of view from which they may be 

 regarded, whether as consisting of abortive flattened branches when the 

 former term is applied, or of a flattened and expanded petiole, or of coherent 

 leaves, or of an expanded combination of leaves and petiole — to either of 

 which the term phyllodia is applied. As, however, these organs develope 

 flower-buds, a process of which true leaves are incapable, it is evident that 

 they cannot be regarded merely as connate leaves, or any modification of 

 leaves and petioles, so that the term cladodia is most closely applicable. 



The cladodia are thick and coriaceous, more or less rhomboid in shape, 

 with the upper margin more or less toothed, lobed, or erose ; the lateral 

 veins radiate from a central vein outwards, so that the organ bears a 

 general resemblance to the pinnule of a large species of Adiantum. In 

 P. glauca and P. trichomanoides the cladodia are arranged distichously on a 

 rachis consisting of a peculiarly modified branch, and present the appear- 

 ance of an ordinary pinnate leaf with alternate leaflets, forming in fact 

 pinnate cladodia, the greater portion of which fall off when the lateral 

 expansions have performed their function. But in P. trichomanoides during 

 autumn or early spring a whorl of new cladodia is developed at the apex 

 of an old rachis, the lateral cladodes of which soon after drop off and the 

 rachis becomes a permanent branch. In the spring, male amenta are 

 produced at the apex of a branch and surrounded by a whorl of cladodia 

 with the lateral expansions greatly reduced in size and carrying female 

 cones. This arrangement, however, is liable to several unimportant 

 modifications. In P. glauca the process is somewhat different ; a terminal 

 rachis becomes elongated and thickened, assuming the character of a true 

 branch ; in the following spring the axis is slightly elongated and densely 

 clothed with recurved rudimentary leaves surmounted by a whorl of large 

 cladodia, which carry female flowers instead of lateral cladodia in the lower 

 part of the rachis. 



The female flowers are arranged in amenta, which are one-flowered in 

 P. trichomanoides, two- to four-flowered in P. alpina, and fi-om ten- to twenty- 

 flowered in P. glauca. Each ovule is imbedded between two modified leaves, 

 which become thickened and fleshy as the fruit approaches maturity, and in 

 P. glauca at length woody. In that species the numerous nuts are arranged 

 in slightly interrupted spirals, and in all the species the nuts are -much 

 compressed, and have the lower part invested by an arillode, which is most 

 conspicuously developed in P. alpina. 



