Saxifragaceae - the Saxifrage Family.
This family's members native to western Washington are herbaceous with lobed, basal leaves. Flower parts come in increments of five and the pistil is oblong in shape (Elpel). Native genera include Parnassia, Boykinia, Mitella, Heuchera, Saxifraga, Tolmiea, Tiarella, Lithophragma and Tellima among others. Common lowland species include Tellima grandiflora (fringecup), Tolmeia menziesii (piggyback plant) and Tiarella trifoliata (foamflower).
We spent some time with the Mitellas and keyed out both M. caulescens (slightstemmed miterwort) and M. ovalis (coastal miterwort). M. ovalis is pictured both above and below. Distinguishing characteristics for this genus include shape of inflorescence (shallow bowl or cup), if the flowering stem exhibits leaves, number of filiform lateral segments on the petals, whether the petals are opposite (in line with) or alternate with the stamens and if the inflorescences at the top of the flowering stem mature before those lower down ("flowers blossoming downward" in Hitchcock) or vice versa. Click on the photo above to enlarge and look for the intensely dissected petals. In this species, stamens are alternate the petals (and opposite the sepals) and flowers are blossoming upward (the lower inflorescences are already on their way to bearing seed). General leaf shape among the various species are also surprisingly distinct, spend some time with the drawings in Hitchcock and it all becomes pretty clear. Photograph of the seeds below (seeds are at least partially splash dispersed, dislodged by raindrops and the like).
