Pest Profile
Foxtail
Setaria spp.
Pest Description
Taken from the Missouri Weed ID Guide: http://weedid.missouri.edu//weedinfo.cfm?weed_id=256
Giant Foxtail (picured at top):
| Weed Description: A clump-forming summer annual with a seedhead that resembles a foxs tail. A weed of many agronomic crops, turf, landscapes, and nurseries. Found throughout the United States, especially on fertile soil. |
| Seedlings: Leaves are rolled in the bud, leaf sheaths are mostly without hairs, but the leaf blades have many short hairs on the upper leaf surface and along the leaf margins. The ligule of the seedlings is a fringe of hairs approximately 1/2 mm long, often very difficult to see with the naked eye. |
| Leaves: Leaf blades may reach 16 inches in length and 15 to 25 mm in width, and are generally covered with many small hairs on the upper leaf surface, except near the leaf base. Auricles are absent and the ligule is a fringe of hairs reaching 3 mm in length. |
| Stems: Erect, round, usually without hairs, reaching 3 to 4 feet in height. |
| Flowers: The seedhead is a cylindrical, bristly panicle that becomes drooping with maturity. Spikelets are approximately 3 mm long, green, and each spikelet has 1-3 bristles that are 5-10 mm long. |
| Roots: A fibrous root system. |
| Identifying Characteristics: Characteristic foxtail-like seedhead that droops when mature and leaves with many hairs on the upper leaf surface, which helps to distinguish this weed from both Green Foxtail (Setaria viridis) and Yellow Foxtail (Setaria glauca). Giant foxtail may be identified by the presence of many short hairs on the upper surface of the leaf blades, unlike the other foxtails. Additionally, giant foxtail is generally larger and has a nodding seedhead, unlike the other foxtails. |
Green Foxtail (pictured at bottom):
| Weed Description: A clump-forming summer annual with a seedhead that resembles a foxs tail. A weed of many agronomic crops, turf, landscapes, and nurseries. Found throughout the United States. |
| Seedlings: Leaves are rolled in the bud, leaf sheaths and blades without hairs, but the leaf sheaths often have slightly hairy margins. The ligule is a row of hairs approximately 1/2 mm long, therefore this is rarely seen by the casual observer. |
| Leaves: Leaf blades may reach 12 inches in length and 5-15 mm in width, and are most often without hairs or only very sparsely hairy. The leaf sheath is closed and is without hairs, except along the margin near the mouth. The ligule is short and fringed with hairs to 2 mm long. |
| Stems: Erect, without hairs, bent at the nodes, may be branched at the base, reaching 3 feet in height. |
| Flowers: The seedhead is a cylindrical bristly panicle, reaching 6 inches in length and 1/3-2/3 inch in width. Spikelets are approximately 3 mm long, green, and each spikelet has 1-3 bristles that are 5-10 mm long. |
| Roots: Fibrous. |
| Identifying Characteristics: Characteristic foxtail-like seedhead and leaves with no hairs, which helps to distinguish this weed from both Giant Foxtail (Setaria faberi) and Yellow Foxtail (Setaria glauca). Giant foxtail may be identified by the presence of many short hairs on the leaf blades, unlike the other foxtails. Yellow foxtail is also similar to green foxtail but has long wiry hairs on the leaf blades where the leaf blades and sheaths meet. |
Yellow Foxtail:
| Weed Description: A clump-forming summer annual with a seedhead that resembles a foxs tail. A weed of many agronomic crops, turf, landscapes, and nurseries. Found throughout the United States, especially on fertile soil. |
| Seedlings: Leaves are rolled in the bud, leaf sheaths are without hairs, but the leaf blades have long silky hairs on the upper surface near the leaf base (shown in picture on left). The ligule is a fringe of hairs approximately 1/2 mm long, often very difficult to see with the naked eye. |
| Leaves: Leaf blades may reach 12 inches in length and 7 to 12 mm in width, and have long silky hairs at the leaf bases. Auricles are absent and the ligule is a fringe of hairs reaching 2 mm in length. |
| Stems: Stems are erect, often flattened, without hairs (glabrous), reaching 3 feet in height, and often with a reddish tint at the base. |
| Flowers: The seedhead is a cylindrical bristly panicle, reaching 6 inches in length and 1/3-2/3 inch in width. Spikelets are approximately 3 mm long, green, and each spikelet has 1-3 bristles that are 5-10 mm long. The bristles turn yellow at maturity, giving the plant its name. |
| Roots: A fibrous root system and stems that do not root at the nodes. |
| Identifying Characteristics: Characteristic foxtail-like seedhead that appears yellow when mature and leaves with long silky hairs at the base only, which helps to distinguish this weed from both Giant Foxtail (Setaria faberi) and Green Foxtail (Setaria viridis). Giant foxtail has many short hairs on the upper surfaces of the leaf blades, unlike yellow foxtail which only has a few long, silky hairs near the leaf base. Similarly, green foxtail has no hairs on the leaf blades or at the leaf bases. |
Pest photo source
Dr. Dallas Peterson, Agronomy, KSU