Devils in the Mountains — Prickfoot, ‘Eryngium vesiculosum’

By Roger Farrow

June 2023

We are all familiar with the Blue Devil, Eryngium ovatum, that iconic plant of temperate grasslands and a good indicator species of good quality native grassland. It belongs to the carrot family, Apiaceae. There are 4 native species of Eryngium described in Australia plus 4 undescribed species. The former are found in widely different habitats. I have seen E. paludosum, growing in swamps in the Narrandera irrigation area and there is E. expansum growing on rainforest margins that I have not seen. But this is the first time I have encountered E. vesiculosum that was spotted by one of our eagle-eyed young members on a visit to Sparkes Plain at the edge of Bago State Forest, east of Tumbarumba, at an altitude of 1100 m.

It was growing in a sward of short grasses and sedges in a swamp along a creek line. As you can see from the picture, the plants are solitary, small and easily overlooked. It is a short-lived perennial like most native Eryngiums. The close up shows a typical Eryngium flower head with a cluster of blue flowers below which is a rosette of blue bracts and a basal rosette of greenish toothed leaves just visible among the sedge leaves. Its common name, Prickfoot, is very apt. Some anthers and lobed stigmas protrude from the simple flowers. The pollinators are unknown but are likely to be generalist bees, flies and beetles.

According to Plantnet, E. vesiculosum is widely distributed across the NSW Tableands in swampy ground, but nowhere common, although that may be because it is easily overlooked.

A word about the genus Eryngium (source Wikpedia). There are about 250 species that are found worldwide although the centre of diversity is South America. Several are garden plants such as sea holly and at least 4 species have become naturalised in Australia. Its distribution over 4 continents suggests to me that it is an ancent lineage of Apiacaeae which possibly evolved when Laurasia and Gondwana were conjoinedi n the mid Cretaceous, 100 million years ago.