Not a large family, mostly tropical. Ours are low herbs, with sour
juice, often with rootstocks or scaly bulbs; leaves with three or
several leaflets; flowers perfect; sepals five, often unequal; petals
five, stamens ten to fifteen; ovary superior, five-celled, the five
styles usually separate; fruit a capsule, containing several or many
seeds. By some botanists this is merged in the Geranium Family.
There are many kinds of Oxalis. The Greek name means "sour," in
allusion to the sour taste of these plants, which contain oxalic acid.
The leaves are alternate, at nightfall the leaflets droop and fold
together; the stamens are ten, five long and five short, all with
anthers, with filaments broadened and united at base.
[Sidenote: =Yellow Wood-sorrel=
_Óxalis corniculàta_
=Yellow
Spring, summer, autumn
Southwest=]
A pretty little plant, a few inches tall, more or less downy all over,
with very slender, reddish, branching stems and light green leaves,
about an inch across and thin in texture. The flowers are over half an
inch across, with clear yellow petals, often tinged with pale red on
the outside, yellow anthers and a green pistil. The capsules are long
and downy.
[Sidenote: =Redwood Sorrel=
_Óxalis Oregàna_
=White, pink
Spring
Cal., Oreg., Wash.=]
One of the most attractive of our woodland plants. The succulent,
hairy, reddish flower-stalks, about six inches tall, with two small
bracts near the top, spring from a clump of root-leaves. The larger
leaves are three inches across, with long leaf-stalks, pale and hairy
on the under side, rich green on the upper, each leaflet marked with an
irregular blotch of pale green. The younger leaves are lighter green
than the older ones and in the bud are neatly folded together, the
middle leaflet inside the other two. The leaflets fold back, when it is
either too hot or too cold to suit the plant. The delicate flowers are
about an inch and a half across, white, pale pink, or rose-color, often
veined with deeper color and with a spot of yellow at the base of each
petal, and well set off by the foliage, which makes patches of rich and
variegated green in dense forest shade.
[Illustration: Yellow Wood-sorrel--Oxalis corniculata.