ROCK- ROSE. 42 



Rock-rose (Hdiarithemum vulgare). 



On our chalk-downs, and on banks in gravelly soils, from 

 June to September the pale yellow flowers of the Rock-rose are 

 abundant. In spite of its plentifulness, however, it is not 

 among those flowers that are generally known, except to the 

 botanist. The rest of the world probably includes it among 

 the buttercups, with which it has no relationship. The plant 

 is shrubby, with a creeping rootstock ; its branches trail on the 

 ground among grass and low herbage. It is therefore by no 

 means a conspicuous plant, though it occurs in considerable 

 masses, and is perennial. The leaves are small, oblong, with 

 an even margin ; the upper surface hairy, the lower downy. 

 They are arranged in pairs on the stem, and provided with 

 stipules. 



The flower-bud is protected by only three sepals, but there 

 are two others reduced to the size and shape of stipules ; and 

 so their number really corresponds with the five somewhat 

 flabby petals, which have the softness of the poppy rather than 

 the stiffness of the buttercup. The stamens that surround the 

 pistil are a multitude ; they are also irritable, and on being 

 touched fall back from the pistil. The plant is common through- 

 out the country, except in Cornwall and West Scotland, in which 

 districts it is rare. The name is Greek, and signifies sunflower. 



There are three other British species : 



I. White Rock-rose (H. polifoliuut). Similar, but more shrubby ; margins of 

 leaves curled back. Flowers white. Very rare. Stony places in Somerset and 

 South Devon. May to July. 



II. Spotted Annual Rock-rose (H. guttatuni). An Annual, of erect habit ; the 

 lower leaves opposite, without stipules, the upper alternate, with stipules. Petals 

 wedge-shaped, yellow, with a red spot at the base of each. Stony places, Anglesea 

 and Holyhead ; very rare. More freely near Cork and in the Channel Islands. 

 June to August. 



III. Dwarf Rock-rose (H. canum). More woody than the others; stems trail- 

 ing. The whole plant hoary^ and much branched. Leaves opposite, without 

 stipules. Flowers yellow, not numerous. May to July, from Glamorgan to West- 

 moreland. 



