Wild Asparagus

Forest and Bird, Volume 22, Issue 1, 1 February 1991, Page 4

Wild Asparagus

IVE SPECIES of asparagus have become wild in New Zealand: climbing asparagus (Asparagus scandens), smilax (A. asparagoides), asparagus fern (A. setaceus), bushy asparagus (A. densiflorus) and edible asparagus (A. officinalis). Edible asparagus, when left, grows into a small bushy shrub with erect branches. It is native to Eurasia and North Africa and has sparingly naturalized in New Zealand. The other four asparagus species are scramblers or low climbing vines and are all native to southern Africa. They are grown in New Zealand as ornamentals and have escaped; two of them are problem weeds. All asparagus species have fleshy roots and tiny true leaves, which may possess a basal spine as in asparagus fern. Cladodes (flattened stems) are the larger leaflike structures which are usually whorled around the stem;

their shape and size is characteristic for each species (see Table). Their small flowers possess six segments which give a clue that asparagus is a member of the lily family (and not a fern). The fruit is a fleshy berry containing one to several seeds which are dispersed by birds. The four asparagus vines are relatively recent weeds in New Zealand with their first naturalised occurrences being from the 1950s (smilax and climbing asparagus) to the 1970s (asparagus fern and bushy asparagus). All four are increasing in abundance and distribution. In a relatively short time climbing asparagus is looking to become one of the worst forest and shrubland weeds in the warmer parts of New Zealand. Smilax is similar to climbing asparagus but has less of an impact on native vegetation. Both occur as far south as Wellington and