In a world flora that harbors pollinators as diverse as slugs, mosquitoes, honey-possums, hummingbirds, and thrips; involving mechanisms as bizarre as pseudocopulation, pseudoaggression, and floral fermentation; and with reproductive structures as simple and ephemeral as the buttercup or as complex and long-lived as the Banksia inflorescence, it is very strange indeed that ants have not played a greater part. There are very few well-documented cases of pollination by ants. On the contrary, ants are widely regarded as thieves, parasitizing plants by taking floral rewards intended for pollinators, without performing the movements necessary for pollination (McDade & Kinsman 1980; Wyatt 1981; Fritz & Morse 1981; Willmer & Corbet 1981; Schaffer et al. 1983), or by simply chewing floral organs such as the style and ovary (Galen 1983).

Ant pollination has been reported a number of times: Herniaria ciliolata (Proctor & Yeo 1973), Orthocarpus pusillus (Kincaid 1963), Polygonum cascadense (Hickman 1974), Glaux maritima (Dahl & Hadac 1940), Seseli libanotis (Hagerup 1943), Morinda royoc, Cordia brownei (Percival 1974), Rohdea japonica (Migliorato 1910; but disputed by van der Pijl 1955), and Microtis parviflora (Armstrong 1979). Diamorpha smallii (Crassulaceae) was studied by Wyatt (1981) and Wyatt and Stoneburner (1981), who showed that this diminutive plant is also pollinated by ants, especially Formica shaufussi and F. subsericea. Pollen adheres to the hairs and integumental sculpturing of these ant species. They visit the flowers systematically but the degree of dependence on ant-borne pollen for seed set remains unknown.