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.
Flower-heads - Composite, the numerous, small, dull, white heads of tubular florets only, crowded in a scaly involucre and borne in spreading, flat-topped terminal cymes. Stem: Stout, tall, branching above, hairy, leafy. Leaves: Opposite, often united at their bases, or clasping, lance-shaped, saw-edged, wrinkled.
Flowering Season - July - September.
Distribution - From the Gulf States north to Nebraska, Manitoba, and New Brunswick. Frequently, in just such situations as its sister the Joe-Pye weed selects (p. 148), and with similar intent, the boneset spreads its soft, leaden-white bloom; but it will be noticed that the butterflies, which love color, especially deep pinks and magenta, let this plant alone, whereas beetles, that do not find the butterfly's favorite, fragrant Joe-Pye weed at all to their liking, prefer these dull, odorous flowers. Many flies, wasps, and bees also, get generous entertainment in these tiny florets, where they feast with the minimum loss of time, each head in a cluster containing, as it does, from ten to sixteen restaurants. An ant crawling up the stem is usually discouraged by its hairs long before reaching the sweets. Sometimes the stem appears to run through the centre of one large leaf that is kinky in the middle and taper-pointed at both ends, rather than between a pair of leaves.
An old-fashioned illness known as break-bone fever - doubtless paralleled to-day by the grippe - once had its terrors for a patient increased a hundredfold by the certainty he felt of taking nauseous doses of boneset tea, administered by zealous old women outside the "regular practice." Children who had to have their noses held before they would - or, indeed, could - swallow the decoction, cheerfully munched boneset taffy instead.
The bright white, wide-spread inflorescence of the White Snakeroot, White or Indian Sanicle, or Deerwort Boneset (E. ageratoides) is displayed from July to November in the hope of getting relief from the fiercest competition for the visits of butterflies, honey and other small bees, wasps, and flies. From July to September the vast army of composites appear in such hopeless predominance that prolonged bloom on the part of any of their number is surely an advantage. In the rich, moist woods, or by shady roadsides, where it prefers to dwell, the white sanicle makes a fine show. Above its fringy bloom how often one sees the exquisite little lavender-blue butterflies (Lyccvna pseudargiolus) pausing an instant to drain the tiny cups of nectar, and usually transferring pollen from the protruding styles (see p. 148) as they flit to another cluster.
The opposite, petioled leaves, broadly oval at the base, taper-pointed, coarsely toothed, three-nerved, and veiny, are thin and easily skeletonized by the insects that enjoy the leaves of all this clan of plants. From one to four feet high, the White Snakeroot grows in the United States and Canada as far west as Nebraska.
Closely allied to the eupatoriums, and with similar inflorescence, is the Climbing Boneset or Hempweed (Willughbaea scan-dens) - Mikania scandens of Gray. Straggling over bushes in swamps, by the brookside thicket, or in moist, shady roadsides, the vine reveals its kinship to the boneset instantly it comes into bloom in midsummer, although its flower clusters are occasionally pinkish. The opposite, petioled leaves are quite different from the boneset's, however, being heart-shaped at the base, and taper-pointed, somewhat triangular, two to four inches long, and one or two inches wide. From Massachusetts and the Middle States even to South America and the West Indies is its range.