A walk in the park

Hydrocotyl elegans, one of the 19 representatives of this genus occurring in Queensland.

Walked the dog through Greendale Park today, as we have done many times before, but came across a patch of Hydrocotyl growing in a damp swale. Immediately struck me as unusually glabrous, and turned out to be my first ever observation of H. elegans, a rather restricted range species endemic to Queensland and New South Wales. In fact, there are only 174 records on iNaturalist, and urban south-east Queensland is the global headquarters of its distribution (see map below). The skew of records towards to a heavily urbanised region is no doubt in part owing to the urbanised distribution of iNaturalist users, and this is a species with outlying populations west of Gladstone and in the Atherton Tablelands, which don’t really show up on the map. There seems to have been some taxonomic confusion, and I can’t quite piece together the full story, but see https://doi.org/10.54102/ajt for a recent treatment.

This all brings home to me that even something as simple as a walk in a local park can generate biodiversity records that contribute meaningfully to our accumulating understanding of nature.

Records of Hydrocotyl elegans in iNaturalist up to 30 Aug 2025.