25

C—lB

Care.r puinila is a small sedge, which, like other sand-binding " grasses," can increase enormously by vegetative means. Its low stature and the bending downwards of its leaves does not enable il lo withstand the drift of the dune proper, though very useful for wind-resisting, and it is in consequence confined to the sand-plains. It is also possible its water-requirements may be greater than those of the preceding plants. There is a slender rhizome about | in. in diameter, which may extend for many feet, giving off small bunches of four to six fully developed leaves at intervals. Tin' leaves are mass-like, sheathing at the base, the sheaths overlapping. The blade is thick and coriaceous, I ft. or more in length, but frequently less, and J in. or more in breadth. It lapeis gradually to a fine point, is glaucous-green in colour, deeply concave on its upper surface, at first erect and then curving until its apex almost meets the ground. The roots are long and slender. The culms are short, stout, and about fi in. tall. The utricle is large, turgid, and about j in.' long. (£) Arundo conspicua (Toetoe-kakaho ; New Zealand Heed). Found only in New Zealand, on almost all dune-areas of any magnitude. Also a very common plan! without the dunes, occurring from sea-level to about I,oooft. altitude, chiefly 'n wet ground, including actual swamps. It is absent in the Kermadec and Subantarctic botanical provinces. Arundo conspicua is a very tall grass, forming enormous dense lussocks after the manner of the pampas-grass (Cyueriuiu ari/enleum). There is a stout short rhizome which can grow upwards as it is buried. The leaves are long, narrow, coriaceous, flat or involute, and t heir nerves st ronglydeveloped. When in bloom the plant is very showy with its long shining yellowish-white panicle, I ft. lo 2ft. in v length. (r/.) Coprosma acerosa (the Sand-coprosma). Found only in New Zealand, where it occurs on all dunes, excepting in the Kermadec and Subantarctic Islands. Coprosma acerosa is a low-growing shrub, which forms flattened cushions (see Flint o No. 22). or thick mats. 2 ft. or so in depth and I or 2 yards in length, made up of wiry, interlacing twigs, conspicuous through their orange or reddish colour. The main stems are extremely flexible and rope-like. ,';, in. or more in diameter, prostrate, and covered with thick brown bark. Such are generally buried in the sand, marking a former surface ; or. at any rate, they are quite concealed by the interlacing twigs. The stems forming the cushion are very wiry, flexuous, and flexible. The branching is at right angles or thereabouts, and frequently only from the flanks of the stem. The ultimate twigs are almost straight, and from ] in. to 3 in. or more. long. The leaves are in opposite pairs on much-reduced branchlets, pressed closely to the stem, an equal amount of naked stem being between them. They are linear, about Jin. long, thick, coriaceous, pale or yellowish green. The roots are extremely long, but short adventitious roots are frequently given off from the peripheral twigs, the plant in thai case being able in some degree to rise above the drifting sand. The flowers are dioecious. The drupe is fleshy, globose, J in. long more or less, translucent, white stained with pale blue. (i.) Pimelea arenaria (the Sand-pimelea ; Aute-taranga, Torohelr). Found only in New Zealand ; common on dunes everywhere, except in Stewart Island, the Kermadec Islands, and the Subantarctic Islands. Pimelea arenaria is a close-growing, much-branched, low shrub, its final branchlets erect and forming close masses. The main stems are cord-like, but not as flexible as in Coprosma acerosa, frequently several feet in length, thus having the faculty of lengthening as they are buried. The shrub is leafy at the periphery only for a depth of about 2 in. to 4 in. The prostrate branches finally give off erect, straight twigs, which branch corymbosely at a narrow angle, thus giving a flatfish top to the shrub. The ultimate and subultimate twigs are alone leafy. The leaves are of a broadly ovate type, about fin. long, closely covered beneath with appressed silky hairs, as are also the final twigs. The buds fit in with the station, the hairs of the leaf affording special protection. The flowers are in close heads at the tips of the branches, and are polygamo-dioecious. The drupe is white and fleshy. The roots are of great length, and adventitious roots are fairly abundant from the uppermost branches, the rest of the shrub being beneath the sand to a variable depth. From the preceding description it may be seen thai both /'. arenaria and Coprosma acerosa are sand-binders to a limited degree, and can with a slow drift continue to grow upwards and rejuvenate themselves, thanks to the power of putting forth adventitious roots from the subultimate twigs. (k.) The Dune Species of Cassinia. Cassinia retorta, C. leptophylla, and G. fulvida are found in the northern, central, and southern botanical provinces respectively, but the last-named also occurs in the central province. None are exclusively dune-plants, but C. retorta is almost so, while C. fulvida ascends to the subalpine belt. All are readily reproduced from seed, and have extended their range since the settler arrived. Cassinia leptophylla may be taken as the type of the dune cassinias. It is a shrub of the cricoid habit, from 3 ft. to 5 ft. tall, or even more The main stems are few, naked, and not much branched at first, but above they branch abundantly into slender leafy twigs, which finally give off at a narrow angle flexible straight branchlets, which are covered with a moderately loose cottony greyish tomentum. These final shoots form close masses ol leaves, but those of one branch are distinct in themselves, and do not mingle with those of the next. The leaves are very small, narrow, linear or linear-spathulate, T V in. to Jin. long, patent or semi-imbricating, coriaceous and moderately thick, bright shining green on the upper surface but tomentose beneath, the tomentum being slightly tinged with yellow. The bud-leaves imbricate ;

4—C. 13.