[Illustration: Rumex hymenosepalus]
Common names: WILD-RHUBARB, DOCK, SORREL, _CANAIGRE_
Arizona and California deserts: (_Rumex hymenosepalus_). Pink-green.
March-April.
Texas desert: (_Rumex mexicanus_). Pink-green. Summer.
Buckwheat family. Size: Coarse perennial up to 2 feet tall.
Sturdy, conspicuous flower and seed heads together with the large leaves
of these coarse, roadside plants, although hardly to be considered as
beautiful, attract considerable attention and arouse the curiosity of
the observer. Some species are garden weeds introduced from Europe. In
the desert, the large, coarse leaves and pinkish flower stalks make
quite a showing in sandy washes and along the roadsides as early as
March and April. The plant is being considered as a source of tannin
(from its tubers) to replace that formerly obtained from Chestnuts.