330 THE STORY OF PLANT LIFE 



called by Linnaeus because they respond to changes 

 in the atmosphere or light intensity. It opens, in 

 fact, at nine a.m. and closes at three p.m. as a rule. 

 The only insect that visits it also is of the '* go-to- 

 bed-at-noon " type. The name Pimpernel is from 

 the Latin bipennella, referring to the pinnate leaves 

 in some plants. 



So common a plant as this is to be found in all 

 parts of the country, but it is rather less common in 

 mountainous districts, as in West Scotland, Wales, 

 the Lake District, and it rarely ascends above the 

 zone of cultivation (looo feet). 



The habitat is cornfields, fields and waste places, 

 gardens, and sandhills by the sea. It occurs in the 

 sand dune formation. I have found it on shingle on 

 the foreshore, along with other inland weeds. It 

 also occurs on chalk in chalk grassland. 



The habit is trailing or creeping. The stem is 

 four-angled, with water furrows, erect occasionall}^ 

 or prostrate, then ascending, the plant being smooth 

 and dotted with black dots or glands, much branched. 

 The leaves are opposite, rarely in whorls of three 

 to four, entire, ovate to oblong, occasionally heart- 

 shaped, acute, stalkless. 



The flowers are scarlet with purple claws, in the 

 axils, on slender stalks in flower, curved downwards 

 in fruit, longer than the leaves. The sepals are 

 narrow, with a long point. The corolla is wheel- 

 shaped, five-cleft like the calyx. There are five 

 stamens. The fruit is a capsule or pyxidium, which 



