Intermixed with this most richly attired of all the asters is the Riddell golden-rod (Solidago Riddellii); quite different from all the other Solidagos in having the stems clothed with long, smooth, narrow leaves, which gradually curve upward and then describe a half circle downward. The large clusters of flowers in the medium-sized heads have a depth of auriferous color which can not fail to attract all lovers of yellow. The golden-rod most nearly like the above is Solidago rigida, an earlier bloomer but holds its own against the early frosts. As the name suggests, the stem is large and stiff or rigid, the leaves are sessile, large, thick, and the heads of the blossoms form a broad, flat-topped inflorescence, standing three or more feet from the high, dry prairie soil. Among the other golden-rods were Solidago speciosa and the altogether common and yet far from the least attractive species, Solidago canadensis. This furnishes a serious puzzle to the careless student, but the lover of slight differences in plants finds in this species with its various varieties a subject of absorbing interest. Aster longifolia and A. multiflorus vie with each other in making the waste places bright and attractive during the October days, and exhibit their powers to resist the destructive agencies of the closing days of autumn by shaking their leafy stems and bright fresh heads of blossoms in the storms of bleak November. The three asters already named are among the last of all the prairie flowers, and seem to be full of life when the streams are icy in the morning and the sunny side of a log is a favorite haunt of the birds of winter.
Along the small brooks and over the lowland, where the fog damp and chill settle at early sunset, the great sunflower (Helianthus grosse-serratus) may wave its head, while around it is the retirement of the winter condition. Helenium autumnale, with its handsome heads, with lemon-yellow notched ray flowers and peculiar velvety decurrent leaves, is not common but attractive. We do not wonder that it lingers in the lap of early winter, because the atmosphere of its whole being is one of endurance, but of the quiet sort befitting the Quaker and not that of the bully.
But there are many late autumn plants scattered through other than the sunflower family. Along the streams and standing kneedeep in the wasted and decaying rubbish of the borders is the long, leafy stem of the Physostegia virginica, with its slender spike of showy rose and purplish-white blossoms. It is one of the mints in all save the minty quality, and for this peculiar lacking it is often a source of trouble to the tyro in classification. The flowers are complex, the stamens possess an abundance of hairs, in which the circulation of protoplasm may be seen; and, besides, insects visit them.
