2. The Narrow-leaved or Marsh Willow-herb (E. palustre).—A smaller plant, seldom exceeding eighteen inches in height, frequent in bogs and marshes, flowering during June and July. Its stem is round, with two lines of downy hairs on opposite sides; and its leaves are sessile, opposite, very narrow, tapering towards the base, and sometimes slightly toothed. The flowers are small, pink, nodding when in bud, arranged in a terminal raceme. Both flowers and fruit resemble those of the last species except that the stigmas of the former are not divided.
3. The Square-stalked Willow-herb (E. tetragonum or E. adnatum).—A similar plant, from one to two feet high, common in bogs and ditches, and easily distinguished from other species of the genus by the four angles of the stem formed by the downward continuation of the margins of the leaves. The flowers are small, in terminal, leafy racemes, and erect when in bud. The petals are of a rose-pink colour, deeply notched; and the stigma is not divided. This species flowers in July and August.
Our next flower is the beautiful Purple Loosestrife (Lythrum Salicaria—order Lythraceæ), which is abundant in the marshes, ditches, and wet places of most parts of Great Britain. It has a creeping rootstock; a stout, erect, slightly-branched, four-angled stem, from two to four feet high; and sessile, narrow, clasping, entire, acute leaves, two or three inches long, arranged in opposite pairs or in whorls of three or four. The flowers are of a reddish purple or pink colour, nearly an inch across, arranged in whorls on a long, tapering, leafy spike. They have a toothed and ribbed, tubular calyx, with broad inner, and narrow outer segments; oblong, wavy, wrinkled petals; twelve stamens in two whorls of different lengths; and a superior ovary. The time of flowering of this species is July to September.
We have now to note several species of umbelliferous plants that grow in bogs and other wet places. The general features of the order (Umbelliferæ) will be found on p. [167], and the reader should refer to these, if necessary, before attempting to identify the following:—
The Procumbent Marsh-wort (Helosciadium nodiflorum or Apium nodiflorum) is a creeping plant, abundant in ditches and other wet places, rooting at the base, with erect flowering stems that are sometimes very short, but often reach a height of three feet. The whole plant is smooth, with hollow stems; pinnate leaves with from three to nine or more pairs of ovate, bluntly-toothed leaflets; and almost sessile umbels of small, white flowers either opposite the leaves or in the angles of the upper branches. These umbels are compound, with about five or six rays, usually without primary bracts, but with several, narrow, secondary ones. The petals have their points turned inwards; and the carpels are oval, each with five narrow ribs. This plant is commonly seen growing in company with the Water-cress and the Brooklime, and blooms in July and August.
The Water Hemlock.
In ditches we occasionally meet with the Water Hemlock or Cowbane (Cicuta virosa)—a tall plant, from three to four feet high, bearing large, flat umbels of small, white flowers from June to August. Its stem is hollow, furrowed, and branched; and the leaves are large, twice pinnate or ternate, with lanceolate, acute leaflets, generally over an inch in length, the margins serrate or (sometimes) doubly serrate. Comparing this plant with the Common Hemlock (p. [169]), we should note that the secondary bracts of the latter are three in number, almost invariably turned to the outside; and that its calyx teeth are very indistinct, while in the present species they are prominent above the ovary.
Next follow three species of Water Dropwort (genus Œnanthe)—smooth plants, with much-divided leaves and compound umbels of white flowers, with secondary, and sometimes also primary, narrow bracts. In all three species the central flowers of each secondary umbel are perfect and shortly stalked, while the outer ones are on longer stalks, and usually staminate. The petals are notched, with points turned inwards; and the fruits have two rather long styles, are crowned by the five minute teeth of the calyx, and their carpels have each five blunt ribs. The three species referred to are:—
