This large Family includes some acrid-narcotic poisonous species. Buttercups cut and mixed with grass often produce a sore mouth in cattle which eat them. The calyx is sometimes colored like the corolla, and often the latter is wholly wanting. There are many stamens and pistils. Often a head of pistils may be observed, each one producing a single seed. Some species are aquatic, and the leaves under water are finely cut. All the leaves, indeed. may be much divided, as in buttercups, and the flowers may be single or panicled. Besides crowfoots and spearworts, this Family includes anemones, hepaticas, the clematis, marsh marigold, larkspur, and columbine.