298 POPULAR FIELD BOTANY. 
gravelly sea-shores, where it is a great ornament, growing 
frequently within reach of the spray from the waves. 
POLYANDRIA. MOoONOGYNIA. 
THALAMIFLOR-. CISTACE. 
HELIANTHEMUM. (Rock-rosz.) 
Generic Character. Calyw of three equal leaves, or five, of 
which the two outer ones are smaller. Petals five. Seed-vessel 
with three valves. 
HELIANTHEMUM VULGARE. Common fRock-rose. This 
pretty plant is frequent in dry pastures and on open downs, 
in chalky and gravelly soil. It is a procumbent little plant, 
its stem shrubby, leaves opposite, oblong, with a loose bunch 
of very pretty yellow flowers, the leaves furrowed, and the 
petals large for the size of the plant, and delicate looking. 
There are other species, but they are rare. 
