claim: South Island is rarely referred to as the "mainland" of New Zealand.
evidence: Myriophyllum -LRB- watermilfoil -RRB- is a genus of about 69 species of freshwater aquatic plants , with a cosmopolitan distribution .. cosmopolitan distribution. cosmopolitan distribution. The center of diversity for Myriophyllum is Australia with 43 recognized species -LRB- 37 endemic -RRB- .. Its name comes from Latinized Greek , `` myrio '' meaning `` ten thousand '' , or figuratively `` too many to count '' , and `` phyllum '' meaning `` leaf '' .. These submersed aquatic plants are perhaps most commonly recognized for having elongate stems with air canals and whorled leaves that are finely , pinnately divided , but there are many exceptions .. leaves. Leaf. For example , the North American species M. tenellum has alternately arranged scale like leaves , while many Australian species have small alternate or opposite leaves that lack dissection .. leaves. Leaf. opposite leaves. opposite leaves. The plants are usually heterophyllous , leaves above the water are often stiffer and smaller than the submerged leaves on the same plant and can lack dissection .. leaves. Leaf. Plants are monoecious or dioecious , the flowers are small , 4 -LRB- 2 -RRB- - parted and usually borne in emergent leaf axils .. The ` female ' flowers usually lack petals .. The fruit is a schizocarp that splits into four -LRB- two -RRB- nutlets at maturity .. The fruits and leaves can be an important food source for waterfowl , which are thought to be an important source of seed and clonal dispersal .. leaves. Leaf