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 - Dull purplish, very pale or bright reddish purple in close, round, terminal clusters, each flower 1/3 in. or less across, 5-parted, the petals twice as long as the sepals; 10 stamens, alternate ones attached to petals; pistils 4 or 5. Stem: 2 ft. high or less, erect, simple, in tufts, very smooth, pale green, juicy, leafy. Leaves: Alternate, oval, slightly scalloped, thick, fleshy, smooth, juicy, pale gray green, with stout midrib, seated on stalk.
Children know the live-forever, not so well by the variable flower - for it is a niggardly bloomer - as by the thick leaf that they delight to hold in the mouth until, having loosened the membrane, they are able to inflate it like a paper bag. Sometimes dull, sometimes bright, the flower clusters never fail to attract many insects to their feast, which is accessible even to those of short tongues. Each blossom is perfect in itself, i.e., it contains both stamens and pistils; but to guard against self-fertilization it ripens its anthers and sheds its pollen on the insects that carry it away to older flowers before its own stigmas mature and become susceptible to imported pollen. After the seed-cases take on color, they might be mistaken for blossoms.
As if the plant did not already possess enough popular names, it needs must share with the European golden-rod and our common mullein the title of Aaron's rod. Sedere, to sit, the root of the generic name, applies with rare appropriateness to this entire group that we usually find seated on garden walls, rocks, or, in Europe, even on the roofs of old buildings. Rooting freely from the joints, our plant forms thrifty tufts where there is little apparent nourishment; yet its endurance through prolonged drought is remarkable. Long after the farmer's scythe, sweeping over the roadside, has laid it low, it thrives on the juices stored up in fleshy leaves and stem until it proves its title to the most lusty of all folk names.