Virginia Tech Weed Identification Guide

Longspine Sandbur: Cenchrus longispinus

lngspnsndbur3-19b.jpg (142954 bytes) Weed Description: Annual grass with conspicuous burs along the seedhead that may reach 20 inches in height.  Longspine sandbur is primarily found in sandy woods in fields of the coastal plain of the southeastern United States.
Roots: A fibrous root system. cenchrus4-18c.jpg (208136 bytes)
cenchrus4-18.jpg (39849 bytes) Leaves:  Leaves are rolled in the shoot and are without auricles.  Leaf blades may reach 8 inches in length and 6 mm in width and are rough above but without hairs below.  The ligule is a fringe of hairs that is approximately 1 mm long.
Stems:  Sheaths may reach 20 inches in height and are without hairs and somewhat flattened in appearance.  Sheath margins are split at least part way up the stem, and have overlapping margins that are virtually transparent (hyaline margins). cenchrus4-18b.jpg (37432 bytes)
cenchrus4-18d.jpg (48425 bytes) Flowers: Seedheads consist of many round, spiny burs.  Each bur is somewhat hairy and is approximately 5 to 7 mm wide.   Each bur contains 2 to 4 spikelets that are 4 to 5 mm long.
Identifying Characteristics:  An annual grass with a ligule that is a fringe of hairs approximately 1 mm long and a seedhead that consists of several spiny burs.  Once the seedheads appear on longspine sandbur, it should be easily identified as a Cenchrus spp.  However, further investigation may be required as there are several other sandbur species. cenchrus4-18e.jpg (51549 bytes)