Eranthis pinnatifida is native to Honshu, Japan where it grows in humus-rich, well-drained soils in woodlands. The pea-sized tubers are tiny, however this is normal given the tiny sized plant that they produce which rarely exceeds 5cm. A very tough bulb indeed and flowers in January-February and quickly goes dormant in May. Best in half-shade in the coldest spot of your garden, otherwise it will quikcly shrivel away and disappear. Not easily grown if you leave in more southerly countries.