Virginia Tech Weed Identification Guide

Red Rice: Oryza Sativa

Weed Description:  An erect summer annual that may reach 32 inches in height.  Red Rice is primarily a weed of rice and occurs in parts of Texas, Louisiana, Arkansas, and Mississippi where rice is grown.

Roots: A fibrous root system.

Leaves: Mature leaf blades are from 12 to 24 inches long and 7 to 20 mm wide.  Leaves have auricles and also have a long (15 mm) membranous ligule that is triangular in outline.  Some hairs occur in the collar regions.

Stems:  Sheaths are tufted and without hairs except in the collar regions.

Flowers: Seedhead is a loose panicle, often somewhat drooping, reaching a maximum length of 8 inches.  Panicles consist of many spikelets that are 7 to 10 mm long and 2 to 2 1/2 mm wide.

Identifying Characteristics: The presence of auricles and tall membranous ligule are both characteristics that help in the identification of red rice.