Bluebottle or Cornflower (Centaurea cyanus).
The Centaureas are closely allied to the thistles, and share with them that hard-headedness which makes the thistle so good a type of the canny Scot. The Bluebottle must not be sought in the company of the thistles on wastes and in neglected corners of pasture, but, as one of its folk-names indicates, in the cornfield. Beginning to flower in June, it keeps up the display of bright blue until the reapers cut it down.
Bluebottle is a composite flower, and it should afford interest to the reader, when he finds the blossoms, to institute a comparison between it and that of the Daisy or other of the Composites we have already described.
The thin stem is but slightly branched, and the long lower leaves are much cut up and very attenuated. Nearer the summit of the stems the leaves are simpler, and reduced to a very slight width. The stems and the under sides of the leaves are covered with loose cottony fibres. The flower-heads have for involucre a number of greenish scales, with toothed brown margins. The ray-florets are bright blue, their free ends divided into five teeth; the inner or disc-florets are much darker. The stamens are irritable, and if touched withdraw into the tube.
There are five other British species of Centaurea, of which several are rare or extremely local in their distribution. The more frequent species are:—
I. Black Knapweed (C. nigra). Leaves rough, entire or lobed, the lower ones with stalks. The heads large and globose, as much as an inch and a half in diameter. Involucral scales circular, brown, toothed. Florets purple. Common in meadows and pastures. June to September.
II. Greater Knapweed, or Hard Heads (C. scabiosa). The leaves are deeply pinnate, like the lower ones of Bluebottle. Heads as much as two inches diameter. Involucral scales cottony, with dark brown, almost black, margin, and paler fringe. Florets rich purple. Waste places. July to September.
Round-leaved Mallow (Malva rotundifolia).
The Round-leaved or Dwarf Mallow is not so well known as the Common Mallow (M. sylvestris), though it is nearly as common. Its flowers are small, and not nearly so conspicuous as those of sylvestris. Like that plant it is found growing by the wayside and on waste places where garden refuse, etc., is dumped. Our three species of Malva are all perennials, and all possess tough fibrous stems. Those of rotundifolia are downy, and lie along the ground and bear many lobed, often toothed, leaves, whose general outline is circular. The flowers are clustered in the axils, and consist of a five-parted calyx, to which is attached a kind of involucre of three bracts, and five distant petals, their tips with a central notch. There are ten styles, the inner surfaces of which are stigmatic; they curl about in various directions, mingling with the numerous anthers, and so ensuring self-fertilization. The fruit consists of a large number of one-seeded carpels arranged in a circle, but easily becoming detached after ripening. Flowers June to September.