Oxalidaceae.
Wood-Sorrel Family.
Sourgrass
(Oxalis stricta). Also known as Yellow
Wood-Sorrel, Pickleweed, and a number of other names,
many of which refer to the sour taste produced by the
oxalic acid in the leaves. The tiny yellow flowers pop
up in sunny spots everywhere. These plants are quite
at home in lawns, gravel, pavement cracks, and
anywhere else they can get a foothold. The leaves are
like miniature versions of the leaves of their close
relative the shamrock. The angled stems of the
seedpods distinguish this from the closely related Oxalis
corniculata.
Creeping
Wood-Sorrel (Oxalis corniculata). Also
called Lady’s Sorrel. These plants closely resemble
the common Sourgrass (O. stricta), but the
stems of the seedpods do not have the pronounced angle
usually seen in their close cousin. This species is
more urban than the other, not found in many rural
areas, and it is often found, as here, in a beautiful
purple-leaved variety, which seems to favor the
sunniest spots (or perhaps sunlight brings out the
purple color).