II EANUNCULACE^ 53 



The plant is a cornfield weed, affects sandy and 

 gravelly soils, and flowers in May and June. It is 

 widely distributed in the temperate regions of the 

 northern hemisphere, but does not extend far north, in 

 our own country not beyond Cumberland. An allied 

 species occurs in America. The name Myosurus, or 

 Mouse-tail, is well chosen from the elongated receptacle. 



Ranunculus 



The genus is almost world wide, but the greater 

 number of species belong to the northern hemisphere. 

 It extends far into the Arctic regions, and some species 

 rise to great heights. There are at least 150 well- 

 marked species, but some botanists make many more. 

 When the flower first opens, the anthers are turned 

 towards the centre. Gradually the filaments of the 

 outer whorl twist round, so that 

 the anthers which in the mean- 

 time have opened stand just over 

 the nectaries, situated at the base 

 of the petals, and are sure to be 

 brushed by insects coming in 

 search of the nectar. The follow- 

 ing day these stamens move out- 

 wards and their place is taken by _ „. _ 



, , , |_ . •' Fig. 30. — Ranunculus aqua- 



the next whorl. ihlS process con- tUis. The enlarged petal 



tinues until all the stamens have '^l°^l *''" ^^'''^ ^^""^J" 

 had their turn. The leaves, as in 



many herbaceous species, are much cut up, especially the 

 subaqueous leaves of the aquatic Ranunculi (Fig. 30). 



The species of Ranunculus are generally perennials. 

 B. sceleratus is sometimes annual, sometimes biennial. 

 a. arvensis is annual. It is a weed of cultivation, and 

 such plants are generally short-lived. 



The genus falls into two divisions — ( 1 ) those floating 

 in water or creeping on mud, with white flowers and 

 wrinkled carpels ; (2) terrestrial or not floating, with 

 yellow flowers and smooth or tuberculate carpels. The 

 former are often regarded as forming a distinct genus. 



