67 WAYSIDE AND WOODLAND BLOSSOMS. 



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 Sep- 

 tember. 

 The other species are : 



I. Common Mallow (M. sylvestris). Its stems are erect, somewhat hairy. Leaves 

 more distinctly lobed. Flowers large, the petals heart-shaped, pale purple (mauve). 

 The anthers mature before the stigmas, unlike M. rotundifoli(t ) where both organs 



