Onagraceae, the evening-primrose family.
Plant: Delicate, upright, hairy plants, to 16", with small pink flowers on long seed pods growing from axils.
Flowers: Small, 1/4", pink, with four distinctly notched petals, on top of a long seed pod.
Leaves: Both alternate and opposite, simple, narrowly ovate, 1"-4", obscurely toothed, sessile, and hairy. Flowers arise from the axils of the the leaves.
Fruit: Long and thin,1.5"-2", with square cross-section, erect along the stem, growing rapidly while the flower is still blooming on the tip, and persisting for some time before splitting open to release seeds attached to silky hairs.
Habitat: Open damp areas, springs.
This delicate flower might be mistaken for some sort of pink mustard
in general appearance, with its four-petaled flowers and long upright
seed pods; however the flower is at the top of the growing seed pod
rather than at the bottom, making it a member of the evening-primrose
family rather than the mustard family.
The technical terms are "ovary inferior" (flower petals on top) and
"ovary superior" (flower petals on bottom) and the distinction is
an important classification characteristic in botany.
A couple of other small pink to white willow-herbs also occur in our area.
Where to find it:
Near the pond on the north and west sides.