Eranthis
One of the earliest to flower in spring, along with Galanthus (snowdrop). The typically yellow flowers are interestingly structured, as surrounding the flowers is a ruff of dissected leaf-like bracts. The yellow petals are actually petal-like sepals and the true petals, are modified into a ring of small pocket-like nectaries. Grow in semi-shade to full sun, so suitable in a woodland setting, under deciduous shrubs, or near the front of the herbaceous border.