Foamflower (Tiarella cordifolia)
A saxifrage that loves the sides of rocky hills in the woods, especially in a stream valley; these were blooming in late April in a deep hollow in Schenley Park, just above a burbling brook, where it took a bit of acrobatics on the rocks to get near enough to photograph them.
Some forms of this species grow leaves with deep red markings along the veins, and those forms have been developed into cultivated varieties with even more pronounced red markings. All the plants in this hollow in Schenley Park had the red markings on their leaves; the plants along the Trillium Trail in Fox Chapel do not.
Gray describes the genus and the species:
TIARELLA L. FALSE MITERWORT. Calyx bell-shaped, 5-parted. Petals 5, with claws. Stamens long and slender. Styles 2. Capsule membranaceous, 2-valved; the valves unequal. Seeds few, at the base of each parietal placenta, globular, smooth. Perennials ; flowers white. (Name a diminutive from tiara, a tiara, or turban, from the form of the pistil, which is like that of Mitella, to which the name of Miterwort properly belongs.)
T. cordifolia L. Leaves from the rootstock or summer runners, heart-shaped, sharply lobed and toothed, sparsely hairy above, downy beneath; stem (1-4 dm. high) leafless or rarely with 1 or 2 leaves; raceme simple; petals oblong, often subserrate. Rich rocky woods, N. S. and N. B. to Minn., Ind., and southw. in the mts. Apr.-June.