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 - Violet blue, from 1/2 to 3/4 in. across; solitary or 2 or 3 together, seated, in axils of upper leaves. Calyx lobes varying from 3 to 5 in earlier and later flowers, acute, rigid; corolla a 5-spoked wheel; 5 stamens; 1 pistil with 3 stigmas. Stem: 6 in. to 2 ft. long, hairy, densely leafy, slender, weak. Leaves: Round, clasped about stem by heart-shaped base.
Preferred Habitat - Sterile waste places, dry woods.
Flowering Season - May - September.
Distribution - From British Columbia, Oregon, and Mexico, east to Atlantic Ocean.
At the top of a gradually lengthened and apparently overburdened leafy stalk, weakly leaning upon surrounding vegetation, a few perfect blossoms spread their violet wheels, while below them insignificant earlier flowers, which, although they have never opened, nor reared their heads above the hollows of the little shell-like leaves where they lie secluded, have, nevertheless, been producing seed without imported pollen while their showy sisters slept. But the later blooms, by attracting insects, set cross-fertilized seed to counteract any evil tendencies that might weaken the species if it depended upon self-fertilization only. When the European Venus' looking-glass used to be cultivated in gardens here, our grandmothers tell us it was altogether too prolific, crowding out of existence its less fruitful, but more lovely, neighbors.
The Small Venus' Looking-glass (L. biflora), of similar habit to the preceding, but with egg-shaped or oblong leaves seated on, not clasping, its smooth and very slender stem, grows in the South and westward to California.