The Water Crowfoot is really a white Buttercup, and it likes to grow in ponds or in rivers that run very slowly. The flowers are at their best in May and June. These flowers have five glossy white petals, and each petal has a yellow patch at the foot. Behind these beautiful white petals there are five green sepals which fold back close round the flower-stalk. Within the flower there are stamens with thick yellow heads, growing in a circle round a small green knot which holds the seed-vessels. This Water Crowfoot has two kinds of leaves. Some grow underneath the water, and these leaves are divided into fine hairs, which are each forked at the end. The water runs very easily through these hairs. But those leaves which are above the water are solid. They are dark green and glossy, and are nearly round. Each leaf is divided into three parts, and sometimes the edges are cut up, and often they are quite smooth. You may sometimes find a leaf with one-half made up of hairy threads while the other half is solid. PLATE XVI: 1. SHEPHERD'S PURSE 2. COMMON SCURVY GRASS 3. HAIRY ROCK CRESS 1. SHEPHERD'S PURSE The Shepherd's Purse is a very common plant, and it is not at all attractive. It is found all summer by the roadside and in waste places. The flowers grow close together on short stalks near the top of a spike. They are very small, with tiny white petals, and those flowers which grow lowest on the spike always come out first. The buds are in a cluster at the very tip of the spike. After the flower is withered, the seed-vessel, which still clings to the end of the short stalk, begins to swell. It looks like a small green heart, with a hard knot in the centre. You will easily recognise the Shepherd's Purse by these seed-vessels, which are far more noticeable than the tiny white flowers. This plant has two kinds of leaves. Those that grow close to the ground have short stalks, and they spring from the root in the form of a rosette. Each leaf is long and narrow, and the edges are deeply cut up, nearly to the centre vein of the leaf. But the Shepherd's Purse has other leaves which grow further up the flower-stem. These are shaped like the head of an arrow, and at the bottom they clasp the stem closely. Both kinds of leaves are usually hairy all over, and so are the stalks, but sometimes you find plants where they are quite smooth. 2. COMMON SCURVY GRASS The Common Scurvy Grass likes to grow on muddy shores and on rocks by the seaside, where you will find its masses of white flowers all summer. The flowers grow close together in a cluster on short stalks. Each flower has four white petals, which are sometimes tinged with purple. The four tiny sepals are tinged with purple too. And the buds which are crowded together at the end of the cluster are nearly all purple.