ˈrüˌmeks noun
Usage: capitalized
Etymology: New Latin, from Latin, sorrel
: a genus of herbs and shrubs (family Polygonaceae) that are mainly native to north temperate regions and have small flowers in axillary clusters often aggregated in a large panicle and 3-angled wingless fruit enclosed in a persistent perianth whose inner segments often bear conspicuous tubercles — see canaigre , dock I 1