Virginia Tech Weed Identification Guide

Sweet Vernalgrass: Anthoxanthum odoratum

sweetvernal12-20.jpg (196145 bytes) Weed Description:  A perennial or winter annual grass that often produces a noticeable seedhead by April or May in many of Virginia's hay fields.  Sweet vernalgrass gives off a distinctive,   sweet-smelling odor when mature.  This plant is most commonly a weed of pastures, hay fields, roadsides, and ditch banks that is found throughout the southeastern United States and into Kentucky and West Virginia.
Leaves:  Leaves are rolled in the sheath and may reach 10 mm in width.  Upper and lower leaf surfaces, as well as the leaf margins, usually have short hairs.  Leaves are without auricles and have a membranous, sometimes toothed, ligule.  Ligules are generally 3-6 mm in length. sweetvgrass5-21.jpg (137687 bytes)
sweetvernal9-19.jpg (91181 bytes) Stems:  Sheaths are round and generally without hairs except near the top.  Sheaths are split and have overlapping margins that are essentially transparent (hyaline).  Plants may reach 2 feet in height.

Roots:  A fibrous root system.

Flowers: A brownish-yellow spike that is approximately 3/4 to 2 3/4 inches long and 1/2 to3/4 inch wide.  Each spike contains many spikelets that are approximately 6 1/2 to 8 1/2 mm long. sweetvernal5-4b.jpg (226758 bytes)
sweetvernal5-4.jpg (80231 bytes) Identifying Characteristics:  Plants with brownish-yellow spikes and distinctive sweet smell.  Additionally, the relatively early appearance of this grass in Virginia helps in its identification.