The study of wild flowers would become a very dull and monotonous subject indeed, if it were not for the continual panorama of interesting changes that it presents when comparing the characters and habits of one species with those of another, or even of the peculiarities of the same species at different seasons of the year. The Rock Rose, for example, has two sets of flowers, and a description of its flowers made when they first appear would compare ridiculously with a description taken from its flowers a month or two later. That is to say, if anyone who is familiar only with its flowers during May and another one who is familiar with them only as they occur during September, should happen to compare notes, each would believe that the other was describing an altogether different species, so far as the flowers were concerned. The first flowers of the Rock Rose blossom during May, June, and July, and they are known as primary, or petaliferous flowers. They are clear, bright yellow in colour, very showy, delicate in texture, and measure an inch in diameter. They have five large, wedge-shaped petals, which are rounded at the top and pointed at the base, and give the corolla the outline of a hextagon. They are crumpled in the bud, and lap each other when expanded. The numerous orange-tipped stamens are usually gathered together in a singular manner on one side of the pistil, and are pressed back flat against the slightly cupped petals. The large, hairy, green calyx has three large and two small divisions - another peculiarity. The flower is solitary, rarely two blossoming at the same time and it resembles somewhat the flowers of the Primrose. It opens but once, and then only in the bright sunshine, lasting but a few hours, and perishing over night. It is delicately constructed, and the petals often drop when the flower is picked. A second crop of flowers occurs during August and September, and is known as secondary or apetalous. These flowers are very small and entirely different from the first ones, and they are borne in clusters at the axils of the leaves. They rarely possess petals, but they do produce a few seeds, and have from three to ten stamens. The calyx is hairy, like the stalk, and the lower side of the leaves. The long, narrow, oblong leaves are set alternately and almost directly on the stalk. Their surface is rough, the midrib is strong, and the edges are slightly curled. Their colour is dark green above and paler and whitish beneath. The erect, slightly branching and woody stalk grows two feet or less in height. It is leafy, and is covered with fine, whitish hairs. This plant is found in fields where the soil is dry, rocky and sandy, from Maine to Indiana, and Wisconsin; south to North Carolina and Kentucky. The Latin name is from the Greek, helios, the sun, and anthemon, a flower. Frostweed is a popular name given to this plant because of its peculiar habit of accumulating frost crystals of snowy whiteness late in the fall, which bursts the bark near the base of the stem and flares out in weird, feathery fantasy, at various angles and degrees of formation.