PSEUDOPANAX CHATHAMICUM. 
Famity ARALIACE.] [Genus PSEUDOPANAX, C. Kocu. 
PuatE 75. 
Pseudopanax ¢chathamicum, 7’. Kirk, Students’ Fl. 223: Cheesem. Man. N.Z. Fl. 236. 
Pseudopanax chathamicum was one of the first plants obtained on the Chatham 
Islands, for it was among those collected by Dieffenbach, the naturalist to the New 
Zealand Company, who visited the group in 1840. His specimens were probably 
imperfect, for otherwise Sir J. D. Hooker, who examined them while engaged in 
the preparation of the “ Flora Nove Zelandix,’ would never have referred them 
to the common New Zealand P. crassifolium. It was also collected by: Mar, Es H. 
Travers, who explored the group in 1863; but apparently a fragment only of the 
plant was brought back. In Mr. Travers’s second visit, made in 1871, a more 
complete suite of specimens was obtained; for Mr. Buchanan, who prepared a 
report on Mr. Travers’s collection which was published in the Trans. N.Z. Inst. 
(vol. vii, p. 333), explicitly says that the Chatham Islands plant differed from the 
New Zealand form in the leaves of the young plant never being deflexed at any 
period of growth. In 1891 Mr. J. D. Enys paid a hurried visit to the group, and 
on his return gave a series of specimens of the plant to Mr. Kirk and myself, at 
the same time stating his conviction that it was specifically distinct from 
P. crassifolium. Shortly afterwards Mr. F. A. D. Cox succeeded in supplying 
Mr. Kirk with a fairly complete set of specimens, in all stages of growth, and 
the plant was accordingly described in the ‘Students’ Flora” under its present 
name, 
As already stated, the chief differences between P. chathamicum and 
P. crassifolium lie in the foliage of the young plants. Both P. crassifolium and 
its near ally P. feroxr have a juvenile stage in which the leaves are very long, 
narrow-linear, and conspicuously deflexed. As the plant approaches maturity 
these linear deflexed leaves gradually become shorter, broader, and more erect ; 
eventually passing into the comparatively short linear-oblong leaves of the adult. 
In P. chathamicum, on the contrary, the leaves of the juvenile stage are 
never much longer than those of the adult, nor much narrower, and are 
never deflexed. The leaves of the mature plant are also larger and broader 
than in P. crassifolium, and the fruit is much larger. These differences are 
quite sufficient to prove the distinct nature of the species. 
Pseudopanax chathamicum appears to be generally distributed in the wooded 
portions of the Chatham Islands. Dr. Cockayne, in his paper on the “ Plant 
Covering of the Chatham Islands” (Trans. N.Z. Inst. xxxiv (1902), 243 et seq.) 
mentions it as an abundant factor in the ordinary lowland forest, in the forest 
of the tableland, and in the somewhat different association found on limestone 
soils. In the lowland forest he classes it as seventh in the order of most 
frequent occurrence, the more abundant. plants being (1) Corynocarpus laevigata, 
(2) Olearia Traversii, (3) Coprosma chathamica, (4) Hymenanthera chathamica, 
(5) Myrsine chathamica, and (6) Corokia macrocarpa. On calcareous soils the 
proportion of frequency is much higher (if I correctly interpret his remarks), 
the Pseudopanax taking the third place. 
For an account of the early development of the seedlings of P. chathamicum, 
together with some remarks on its life-history, reference should be made to 
Dr. Cockayne’s paper in Trans. N.Z. Inst. xxxii (1900), 88. 
PLATE 75. Pseudopanax chathamicum, drawn from specimens supplied by Mr. F. A. D. Cox, ot 
Whangamarino, Chatham Islands. Fig. 1, male flower (x4); 2 and 3, front and back view 
of anthers (x8); 4 and 5, female (or hermaphrodite ?) flowers (x 4); 6 and 7, longitudinal and 
transverse sections of ovary (x 6); 8, longitudinal section of fruit (x 4); 9, embryo (x 12). 
