PLATE 84.—COPROSMA ACEROSA. 
Famity RUBIACE4. | [Genus COPROSMA, Forsvt. 
Coprosma acerosa, 4. Cunn. Precur. n. 477; Cheesem. Man. N.Z. Fl. 257. 
The sea-coast of New Zealand is often fringed for scores of miles by wide- 
spreading sand-dunes, which stretch inland for considerable distances, and 
sometimes reach a height of 500ft. These dunes support a very peculiar 
and characteristic vegetation, so remarkably uniform throughout the entire length 
of the Dominion that many of the species abundant at the North Cape are equally 
plentiful at the Bluff. One of the most prominent and widely spread of these 
species is the subject of the present. plate. 
The discovery of Coprosma acerosa dates back to the first landing of Europeans 
on the shores of New Zealand during Cook’s first voyage, for it was one of the 
species collected by Banks and Solander in Poverty Bay on the memorable 8th 
and 9th of October, 1769. It was fully described and figured by Dr. Solander in his 
manuscript ‘‘ Flora of New Zealand”? under the name of Pelaphia acerosa ,; but, 
as previously explained in this work, his names were never actually published, 
and thus have no standing in systematic botany. After Cook’s departure the 
plant was not again observed until 1826, when the enthusiastic Allan Cunningham 
obtained it in Matauri Bay, a little to the south of Whangaroa Harbour. A few 
years later he published the species in his “ Precursor,” using Solander’s specific 
name of acerosa, and Forster’s generic title of Coprosma. Since then it has been 
proved to be abundant on all sand-dunes of any size, from the North Cape to 
Stewart Island. 
Coprosma acerosa usually forms more or less dense carpets or cushions from 
2 ft. to 6 ft. in diameter, and from 6in. to 4 ft. in height. Its branches are long and 
flexuous, often much interlaced, and are covered with yellowish-green linear 
leaves, generally more or less closely appressed. The flowers are of the type usual 
in the small-leaved section of the genus, and need no description here; but the 
berry is often conspicuous from its pale sky-blue colour and comparatively large 
size, although the latter character is somewhat variable. As already stated, the 
species is abundant on sand-dunes. It has been pointed out by Dr. Cockayne, 
in his ‘“‘ Report on the Sand-dunes of New Zealand,” that it is of considerable 
importance by detaining around it sand which would otherwise be blown inland 
by the wind. It thus acts as a “sand-collector”:; and, if not buried by a too 
liberal supply of drifting sand, is of considerable value for fixing the surface of 
the dune, and thus assisting in its gradual reclamation. 
In the above remarks I have had solely in mind the typical state of the 
species, which, so far as I know, is never found away from the sand-dunes of 
the coast, and which is easily recognized by its peculiar habit and yellow- 
green colour. But, as I first pointed out in my revision of the genus (Trans. 
N.Z. Inst. xix (1887), 245), there is another well-marked variety which is of 
common occurrence in certain inland stations, such as the stony river-valleys 
of the South Island and in the mountainous districts of the North Island. ‘Tt 
can be distinguished by its dark-brown colour, fewer short stout and rigid 
branches, and shorter and more distant coriaceous leaves. The varietal name 
of brunnea was applied to it by Mr. Kirk in his ‘Students’ Flora.” More 
recently Dr. Cockayne has proposed to constitute it a separate species; but, I 
think, quite unnecessarily. 
Puate 84. Coprosma acerosa, male, female, and fruit, drawn from specimens collected on sand 
dunes near the Kaipara Harbour. Fig. 1, male flower (x 6); 2, bracts and calyx (x 6); 3, corolla 
laid open (x 6); 4, female flower (x 6); 5, transverse section of ovary (x 8); 6, longitudinal section 
of ovary (x 8); 7, pyrene (x3); 8, longitudinal section of pyrene (x 5). 
