River Buttercup vs Willisii

Both plants overlap around the foreground and midground, which is the biggest reason they belong in the same comparison.

River Buttercup is a stolon / runner plant that usually reaches about 15 cm tall by 20 cm wide. Willisii is a rosette / crown plant that usually reaches about 20 cm tall by 15 cm wide.

They also share practical benefits such as shrimp refuge and grazing surfaces, so the decision is not only about looks.

The strongest overlap signals are practical: they overlap strongly in placement, especially around the foreground and midground; they offer many of the same practical benefits, including good refuge for shrimp and good grazing surface.

Choose River Buttercup when its exact growth habit fits the open space you have and you want the finished scape to lean toward its shape, texture, or spread.

River Buttercup is the tidier fit when space is limited.

River Buttercup also suits keepers who want high light and recommended added CO2, with moderate growth, moderate maintenance, and intermediate difficulty.

Choose Willisii when its shape, mature size, or planting style gives the scape a cleaner finish than forcing River Buttercup into the same role.

Willisii is the easier keep when you want the simpler option.

Willisii makes more sense in lower-light scapes.

Willisii is the tidier fit when space is limited.

Willisii fits a routine built around low light and optional added CO2, with slow growth, low maintenance, and beginner difficulty.

Role overlap lands at 78/100 and care similarity lands at 64/100. Treat those numbers as a shortcut for the decision, not as a replacement for looking at mature size and placement.

River Buttercup is rooted in substrate with nutrient-rich substrate preferred and feeds mainly as a mixed feeder. Willisii is rooted in substrate with nutrient-rich substrate preferred and feeds mainly as a root feeder.

Lighting expectations are different enough that they do not drop into the same setup equally well.

If the tank already has several demanding plants, the easier choice is the one that matches your existing light, CO2, and trimming routine.

If both are available, pick based on the role you need most: the tidier mature footprint, the better cover value, or the plant that matches your current routine without upgrades.

A practical way to decide is to imagine the tank six months from now. The better plant is the one that still fits the same space after several trims, not the one that only looks right on planting day.