[3] The basis for the modern classification of the Apaiceae was developed by Artedius in the early 18th century and his name for fine-leaved water-dropwort (the basionym), Phellandrium aquaticum, was published after his death by Linnaeus in Species Plantarum in 1753.

[6] However, in 1798 it was placed in the genus Oenanthe (as O. aquatique) by Jean Louis Marie Poiret in the 4th volume of Lamarck's Encyclopédie méthodique Botanique,[7] and it has stayed there ever since.

The specific epithet "aquatica" is the feminine form (nominative, singular) of the Latin word aquaticus, meaning "of water".

[4] The native range is from Ireland in the west, eastwards to central Siberia and from the more southerly parts of Scandinavia southwards to the Mediterranean basin.

[15] It is widespread and common in France and overall has a status of Least Concern, although in Corsica it is considered to be VU (Vulnerable) and in two départements (Midi-Pyrénées and Provence-Alpes-Côte d’Azur) it is classified as EN (Endangered).

[16] In Germany, where it is known as Großer Wasserfenchel (Great Water Fennel), it is considered an indicator of natural floodplain vegetation, and attempts to restore ecosystem function on the Danube have used this species as a measure of success.

[17] In the former Czechoslovakia, fine-leaved water-dropwort is very common and occurs predominantly in shallow reservoirs, oxbows and temporary pools up to 640 m above sea level in the Brdy hills.

It can be very abundant, reaching pest status, in pools with a fluctuating water level, in the year following the drainage event.

[3] Fine-leaved water-dropwort is strictly a wetland plant, occurring in a wide variety of habitats which vary from full sun to medium shade, fresh to slightly brackish water, and from low to fairly high nutrient status.

[20] It is generally more abundant, however, in pools with a fluctuating water level, where it can germinate and rapidly grow on bare mud in the summer.

Three (Prasocuris phellandrii, Hypera adspersa and H. arundinis) are beetles, two (Lixus iridis and L. paraplecticus) weevils, one (Lasioptera carophila) a midge, and two (Depressaria daucella and D. ultimella) are micro-moths.

The fruits are reputed to cause vertigo, drunkenness and narcotic symptoms, and it can easily be confused with other, more deadly species such as hemlock water-dropwort.

Nevertheless, it is reported by ethnobotanists as being used to treat various medical conditions, such as chronic pectoral diseases, dyspepsia, fevers and ulcers.