Yellow Marshwort

Nymphoides crenata
Family: MENYANTHACEAE
What a silly little plant this is! It doesn’t like the container I’ve put it in. It’s too shallow for it, and there’s not room for a good layer of deep, rich mud, which is what it would really like. So it has responded by shrinking its leaves, as it does in the wild when times are tough. It seems to be telling me what a mean old gardener I am.
So I didn’t expect it to flower so happily, with normal-sized flowers which are bigger than the leaves.
In better conditions - still (or slow-flowing) fresh water to 1.5m deep, with a muddy bottom - the leaves are about 12cm long.
This plant dies back to almost nothing in winter. Fresh new growth appears every spring, and spreads across the water by stolons (like those on strawberry plants). Flushes of flowers appear every few days from November to about May.
Like strawberry plants, they are easily reproduced from the plantlets which appear at each node.
This wavy-leafed marshwort is plant of the inland, but is now often seen east of the dividing range, having been introduced there by gardeners. Apparently they like the wavy-edged leaves of our sort rather than the smooth-edged ones of their local native, the very similar Nymphoides geminata.