Ranunculus limosella
from New Zealand

by Ole Pedersen
Reprinted, with permission, from the website of Tropica Aquatic Plants, Denmark
Aquarticles

Ranunculus limosella is a new beautiful plant from Tropica Aquarium Plants. The plant is endemic to New Zealand, where it inhabits the shallow water of the littoral zone of lakes.

R. limosella is amphibious, small (<8 cm), with basal growth from a horizontal rhizome. The emergent form flowers with yellow to purple flowers about 5 mm in diameter. R. limosella is easily confused with various species in the genus of Lilaeopsis but R. limosella has a distinct petiole and blade compared to the more undifferentiated leaf of Lilaeopsis.

Ranunculus limosella

R. limosella is extremely sensitive to eutrophication of its natural habitats due to the limited size of the plant. It cannot reach up towards the light when increasing phytoplankton growth is absorbing the light. In addition, the development of hydro-electric power stations with heavily regulated reservoirs is also threatening R. limosella. Often the water level of the reservoirs fluctuates by several metres over the year, and during long periods the deeper growing populations of R. limosella will not meet their minimum light requirements, leading to a die-off of the deepest growing plants.

Ranunculus limosella

This plant was brought to Tropica as a weed within a shipment of Eleocharis from New Zealand. R. limosella is produced on emergent tables but it grows just as well below water when the high demands of CO2 and light are met. R. limosella is ideal for foreground purposes or in tanks designed or inspired by the Nature Aquarium concept.

After a while R. limosella will form a dense cover under optimal growth conditions. Each pot contains 100 plants or more, so to obtain a faster plant cover, split up the lump into 8 or more pieces and plant the individual pieces about 5 cm apart in a mesh-like structure.