 The bulbous buttercup gets its name from its distinctive perennating organ, a bulb-like swollen underground stem or corm, which is situated just below the soil surface.After the plant dies in heat of summer, the corm survives underground through the winter.Although the presence of a corm distinguishes "Ranunculus bulbosus" from some other species of buttercup such as "Ranunculus acris", the species also has distinctive reflexed sepals.