Harmful plant species entering New Zealand 1963–1967

Summary

Potentially harmful plant species, mainly as seed, are continually entering New Zealand from many parts of the world. During 1963–67 over 1,500 items of botanical interest have been intercepted by the Department of Agriculture§ Port Agriculture Inspection Service and identified to specific or generic level at the Levin Horticultural Laboratory.

Of significant interest were 116 interceptions which included propagules of 65 harmful species, of which 45 have never before been recorded as growing in New Zealand. An appendix lists the harmful species and indicates their probable sources, the means by which they gained entry, and the types of propagule.

The threat from the establishment of harmful species such as Alternanthera repens, Bassia birchii, Colocynthis citrullus, and Cyperus esculentlls is discussed.