[7][8] This species was collected by Julius von Haast in 1862 on the Canterbury Plains, "among grass", and sent to Joseph Dalton Hooker, who in 1864 named it Cotula filiformis.

[10] The genus name Leptinella, from the Greek leptos or thin, refers to the plant's slender ovary; filiformis, from the Latin filum or thread, means thread-shaped.

It grows in grassland and open shrub land on basins, plains, and dry alluvial river terraces up to 600 m (2,000 ft) above sea level.

[4] Almost pure patches of L. filiformis could be found on the lawn, under a canopy of ornamental exotic trees, mixed with introduced pasture grasses and weeds.

[4] In February 1999, Molloy and Department of Conservation (DOC) staff Peter de Lange and Nick Head returned to Hanmer Lodge and collected live plants for propagation.

DOC ranger Jan Clayton-Green had previously encountered the species in 2011 in the Clarence Valley without recognising it as L. filiformis; subsequently-collected plants were grown on until they flowered and their identity could be confirmed.