4o8 DICOTYLEDONS AND CONIFERS 



Rosa rubiginosa, Linn. Sweet-briar 

 Darwin, writing of the Bay of Islands in 1835, says "At Pahia, 

 it was quite pleasing to behold the English flowers in the gardens 

 before the houses; there were roses of several kinds, honeysuckle, 

 jasmine, stocks, and whole hedges of sweet-briar." Polack, writing 

 in 1838, says it is "acclimated" in New Zealand, i.e. in the far north, 

 which was the only part he saw. The early settlers everywhere planted 

 this favourite shrub, as a hedge plant, and everywhere, at least in 

 the North Island, it got away from cultivation and quickly established 

 itself, as a plant most difficult to eradicate. As fruit-eating birds in- 

 creased it increased more rapidly, but there is little doubt that it 

 was largely spread by horses, which will eat the hips, but are unable 

 to digest the hard-walled achenes. Hooker mentioned it in his list 

 of introduced plants in 1864, and it occurs in every subsequent col- 

 lector's lists. It was early recognised as a great pest, and is now most 

 abundant in all parts of the country, though it is a worse pest in the 

 North Island than in the South Island. Cockayne says it is generally 

 absent from wet areas, where the blackberry is the prevailing weed. 

 In the Noxious Weeds Act of 1900, this was one of the three plants 

 which was declared a noxious weed without any reservation; the 

 others being the blackberry and the Canadian (or Californian) thistle. 

 It is fertilised in Europe by Apis mellifica and Bombus terrestris. 



Rosa multiflora, Thunb. 

 First recorded as a wild species in 1869 in the Auckland district 

 by Kirk. In the Manual it is stated to be found "often lingering for 

 years in deserted gardens, etc." 



Cratcegus oxyacantha, Linn. Hawthorn ; Whitethorn 

 Probably introduced at an early date, but began to be scattered 

 as soon as thrushes and blackbirds increased. First recorded as a 

 naturalised plant by W. W. Smith in 1903. Cheeseman (1906) says 

 that it is "scarcely naturalised, but seedlings sometimes appear in 

 the vicinity of planted hedges." In the West Taieri (Otago) I have 

 seen the scarlet mistletoe (Loranthus colensoi) growing freely on this 

 plant. It is being spread by blackbirds. (FL, Oct. to Nov.) 



Visited in Europe by ^^i,y mellifica, Bombus terrestris, Eristalis tenax, 

 Lucilia ccesar and Anobium paniceum ; the latter perhaps for pollen. 

 (See Appendix B, p. 562.) 



Pyrus communis, Linn. Pear Tree 

 Probably introduced by the missionaries into the Bay of Islands 

 and Hokianga districts. It has not gone wild an5Tvhere in New 

 Zealand. In Europe the flowers are pollinated by Apis mellifica, 



