158 



NATURALIZED PLANTS. 



It lias been already stated that one of tlie cliief directions in wliich tlie 

 indigenous flora has been affected by the operations of the settler, is in the 

 displacement of many of its species by naturalized exotics. The extent to 

 which these plants have become established is detailed in an " Account of 

 the Naturalized Plants of New Zealaiid," published in the Transactions of the 

 New Zealand Institute, 1869, which renders it needless to recapitulate the 

 particulars here. A few general remarks on their diffusion in this district 

 will serve as a fitting introdiiction to the following catalogue. 



Many introduced grasses, trefoils, and medicks have formed patches of 

 natural pasture, of considerable value, both on the scoria and clay ; these are 

 often improved by a mixtvire of native grasses, especially Microlcena stipoides 

 and Danthonia semi-anmdaris, and, if the open lands were not so frequently 

 burnt, this self-sown pasture would soon become genera], and that on lands 

 which can only be laid down in artificial pasture at a heavy expense. On 

 waste places, and by road sides, an unsightly appearance is prod\iced by the 

 docks, camomile, mallows, and flea-bane, which eveiy where take possession of 

 disturbed soil. Of these, however, the flea-bane is commonly eaten by cattle 

 when young. 



A few plants have become pests on the light scoria soil ; the sheep's sorrel 

 and the white clover are almost ineradicable in gardens ; Pliytolacea octandra 

 makes its appearance wherever soil is disturbed on the volcanic hills, or by the 

 road sides in their vicinity, and forms large suffruticose bushes, whose spikes 

 of black fruit produce a striking effect; Amaranthus oleraceus is usually 

 associated with it, and less frequently the purslane, which enjoys a wider 

 range of soil. The large moth-mullein rears its tall shafts on the North Head 

 of the "VVaitemata and on Mount Eden, a marked contrast to the vegetation 

 about it. It must have been an early introduction, as Hochstetter speaks of 

 its occurrence in the former locality in 1858. (Euothera stricta appears to be 

 confined to the volcanic hills, where it is usually plentiful. 



In ordinary cultivated land, the milk-weed, Eujihorhia Peplus, and several 

 small speedwells are extremely troublesome, together with a few grasses, 

 especially Digitaria smiguinalis, D. huynifusa, and the canary-grass. 



In every plashy place and moist gully on the Isthmus, Lythrum hyssojnfolium 

 is in abundance, affording a remarkable contrast to the paucity of this plant in 

 its European habitats. 



Black-berries, sweet-briars, and roses sometimes form large thickets, 

 covered with the rampant Senecio scandens, from the Cape of Oood Hope, or 

 more rarely with the tropical Dolichos lignosus. 



The dwarf centaury is abundant on open lands and in paddocks, forming a 

 welcome addition to our native plants ; Aira caryophyllea and Prunella mdgaris 

 are frequently associated with it. 



