This section is from the book "Nature's Garden", by Neltje Blanchan. Also available from Amazon: Nature's Garden; An Aid To Knowledge Of Our Wild Flowers And Their Insect Visitors.
Flowers - White and greenish, about 1 in. across or less, in loose clusters from the axils. Calyx of 4 or 5 petal-like sepals; no petals; stamens and pistils numerous, of indefinite number; the staminate and pistillate flowers on separate plants; the styles feathery, and over 1 in. long in fruit. Stem: Climbing, slightly woody. Leaves: Opposite, slender petioled, divided into 3 pointed and widely toothed or lobed leaflets.
Preferred Habitat - Climbing over woodland borders, thickets, roadside shrubbery, fences, and walls; rich, moist soil.
Flowering Season - July- - September.
Fleecy white clusters of wild clematis, festooning woodland and roadside thickets, vary so much in size and attractiveness that one cannot but investigate the reason. Examination shows that comparatively few of the flowers are perfect, that is, few contain both stamens and pistils; the great majority are either male - the more showy ones - or female - the ones so conspicuous in fruit - and, like Quakers in meeting, the sexes are divided. The plant that bears staminate blossoms produces none that are pistillate, and vice versa - another marvellous protection against that horror of the floral race, self-fertilization, and a case of absolute dependence on insect help to perpetuate the race. Since the clematis blooms while insect life is at its height, and after most, if not all, of the Ranunculaceae have withdrawn from the competition for trade; moreover, since its white color, so conspicuous in shady retreats, and its accessible nectar attract hosts of flies and the small, short-tongued bees chiefly, that are compelled to work for it by transferring pollen while they feed, it goes without saying that the vine is a winner in life's race.
Charles Darwin, who made so many interesting studies of the power of movement in various plants, devoted special attention to the clematis clan, of which about one hundred species exist; but, alas! none to our traveller's joy, that flings out the right hand of good fellowship to every twig within reach, winds about the sapling in brotherly embrace, drapes a festoon of flowers from shrub to shrub, hooks even its sensitive leafstalks over any available support as it clambers and riots on its lovely way. By rubbing the footstalk of a young leaf with a twig a few times on any side, Darwin found a clematis leaf would bend to that side in the course of a few hours, but return to the straight again if nothing remained on which to hook itself. "To show how sensitive the young petioles are," he wrote, " I may mention that I just touched the undersides of two with a little water color which, when dry, formed an excessively thin and minute crust; but this sufficed in twenty-four hours to cause both to bend downwards."
In early autumn, when the long, silvery, decorative plumes attached to a ball of seeds form feathery, hoary masses even more fascinating than the flower clusters, the name of old man's beard is most suggestive. These seeds never open, but, when ripe, each is borne on the autumn gales, to sink into the first moist, springy resting place.
The English counterpart of our virgin's bower is fragrant.