ON THE CHALK 299 



Violacece) — may be found in some limestone and chalk districts, 

 and also on some dry soils removed from calcareous rocks. It has 

 no runners like those of other species, and its cordate leaves are 

 very hairy, on petioles covered with spreading haii's. The flowers 

 are scentless, pale violet or white, with bracts below the middle of 

 the peduncle ; and the spur of the corolla is long, blunt, flattened, 

 and hooked. 



Two species of Flax (order Linacea;) are to be found on chalky 

 soils. One — the Perennial Flax [Linum perenne) — grows in hiUy 

 districts, but is not at all common. It is a slender plant, with 

 numerous wiry stems from one to two feet high ; and sessile, Unear, 

 acute leaves. The petals are of a beautiful sky-blue colour, but 

 so hghtly attached that it is difficult to secure a perfect specimen. 

 The other species — the Narrow-leaved Flax [L. angustifolium) — is 

 moderately common on calcareous hills of the South and West of 

 England. It is very similar to the last, and grows to about the same 

 height, but its many stems are more irregularly bi^anched, and the 

 alternate leaves are hnear-lanceolate. The corolla is of a lighter 

 lilac-blue colour. L. 2>erenne blooms dm-ing June and July, and 

 the narrow-leaved species from June to September. The latter is 

 shown on Plate VIII. 



Quite a number of species of leguminous plants (order Legumin- 

 osce), may, as a rule, be met with on dry soils, but only two common 

 ones may be described as particularly partial to chalk and lime- 

 stone locaUties. These are the Tufted Horse-shoe Vetch {Hippo- 

 crepis comosa) and the Sainfoin or Cock's-head {Onobrychis saliva). 

 The former, represented on Plate VIII, is a low, smooth, prostrate 

 plant, six to eighteen inches long, with yeUow flowers that bloom 

 from May to August. This plant is sometimes confused with the 

 Bird's-foot Trefoil, which it rather closely resembles in general 

 appearance, but it may be readily distinguished by the pinnate 

 leaves and the peculiar form of the pods. The latter are flattened, 

 and break up, when ripe, into from three to six one-seeded, horse- 

 shoe-shaped segments — a feature which has given rise to the popular 

 name. 



The Sainfoin is often cultivated in the South-East of England 

 as fodder for cattle, but may frequently be found growing wild. 

 It is a very pretty, erect plant, from one to two feet high, with 

 dense racemes of rosy-red flowers beautifully striped with a darker 

 . tint. '^ The stem is stout and downy, and the pinnate leaves have 

 membranous stipules and numerous oblong leaflets which terminate 



