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 - Sulphur or greenish yellow, with 5 dark purplish dots, 1 in. across or less, solitary from the leaf axils. Calyx 5-toothed, much inflated in fruit; corolla open bell-shaped, the edge 5-cleft; 5 stamens, the anthers yellow, style slender, 2-cleft. Stem: 1 1/2 to 3 ft. tall, erect, more or less hairy or glandular, branched, from a thick rootstock. Leaves: Ovate to lanceolate, tapering at both ends or wedge-shaped, often yellowish green, entire or sparingly wavy-toothed. Fruit: An inflated, 5-angled capsule, sunken at the base, loosely surrounding the edible reddish berry.
Preferred Habitat - -Open ground; rich, dry pastures; hillsides.
Flowering Season - July - September.
Distribution - New York to Manitoba, south to the Gulf States.
A common plant, so variable, however, that the earlier botanists thought it must be several distinct species, lanceolata among others. A glance within shows that the open flower is not so generous as its spreading form would seem to indicate, for tufts of dense hairs at each side of grooves where nectar is secreted, conceal it from the mob, and, with the thickened filaments, almost close the throat. Doubtless these hairs also serve as footholds for the welcome bee clinging to its pendent host. The dark spots are pathfinders. One anther maturing after another, a visitor must make several trips to secure all the pollen, and if she is already dusted from another blossom, nine chances out of ten she will first leave some of the vitalizing dust on the stigma poked forward to receive it before collecting more. Professor Robertson says that all the ground cherries near his home in Illinois are remarkable for their close mutual relation with two bees of the genus Colletes. So far as is known, the insignificant little greenish or purplish bell-shaped flowers of the Alum-root (Heuchera Americana), with protruding orange anthers, are the only other ones to furnish these females with pollen for their babies' bread. Slender racemes of this species are found blooming in dry or rocky woods from the Mississippi eastward, from May to July, by which time the ground cherry is ready to provide for the bee's wants. The similar Philadelphia species was formerly cultivated for its "strawberry tomato." Many birds which feast on all this highly attractive fruit disperse the numerous kidney-shaped seeds.