Bristle-grasses

Rough Bristle-grass Green Bristle-grass Green Bristle-grass Yellow Bristle-grass



Grasses - Poaceae

See also short-headed grasses.

Yellow Bristle-grass      Setaria pumila

Native throughout warm temperate and tropical regions of the Old World and widely introduced elsewhere. Plants 6-75cm in height, forming loosely tufted clumps or solitary stems. Leaf blades 6-10mm wide, hairless or hairy towards the base. Leaf sheaths rounded, hairy on the margins. Ligule a fringe of silky hairs. Flower spike upright, 1-15cm long. Spikelets 3-3.3mm, globular and densely packed, with 1-2 florets; each spikelet accompanied by 5-10, yellow bristles that bear forward-pointing barbs.

Yellow Bristle-grass Yellow Bristle-grass Yellow Bristle-grass Yellow Bristle-grass
Flower spikes
Flowering spike
Flowering spike
Late flower spike
Yellow Bristle-grass Yellow Bristle-grass Yellow Bristle-grass Yellow Bristle-grass
Single spikelet
Single spikelet
Leaf base
Leaf base and ligule


Green Bristle-grass      Setaria viridis

Native throughout central and southern Europe, south to the Sahelian Region and eastwardS across Asia and south into Australia. Widely introduced elsewhere. Plants 10-60cm in height, forming loosely tufted clumps or solitary stems. Leaf blades 4-10mm wide, hairless. Leaf sheaths rounded, hairy on the margins. Ligule a fringe of silky hairs. Flower spike very variable, typically upright but may arch over in larger, mature specimens, 1-10cm long. Spikelets 2-2.5mm, globular and densely packed, with two florets; each spikelet accompanied by 1-3 bristles that bear tiny, forward-pointing barbs.

Green Bristle-grass Green Bristle-grass Green Bristle-grass Green Bristle-grass
Flower spikes
Flower spike
Flower spike
Flowering spikelets
Green Bristle-grass Green Bristle-grass Green Bristle-grass Green Bristle-grass
Flowering spikelets
Spikelets
Leaf ligule
Leaf ligule


Rough Bristle-grass      Setaria verticillata

Native throughout warm temperate parts of Eurasia, southward throughout Africa and through south-east Asia to Australia; widely introduced elsewhere. Plants to 50cm in height. Leaf blades 3-8mm wide, sparsely hairy. Leaf sheaths slightly compressed, hairy on the margins. Ligule a dense fringe of short hairs. Flower spike upright or slightly nodding, up to 10cm long, often rather open towards the base. Spikelets 2-2.3mm, elliptical, flat on one side with two florets; each spikelet accompanied by 1-3 bristles that bear tiny, backward-pointing barbs. The barbs are distinctive on this species and often snag on nearby vegetation, or even entrap insects. This often results in clusters of flower spikes hooking together and becoming entangled, which doesn't seem to happen with the other species.

Rough Bristle-grass Rough Bristle-grass Rough Bristle-grass Rough Bristle-grass
Flowering spike
Flowering spike
Entangled spikes with trapped
insects
Flowering spikelets
Rough Bristle-grass Rough Bristle-grass Rough Bristle-grass Rough Bristle-grass
Flowering spikelets
Spikelet
Backward pointing barbs
on bristles
Leaf ligule


Adherent Bristle-grass      Setaria adhaerens

Native in the tropics and sub-tropics of Africa, India and the Middle East. Probably introduced in the Canary Islands on rough and disturbed ground. Closely resembles Rough Bristle-grass Setaria verticillata but averages smaller flower spikelets and has hairless leaf sheaths.

Adherent Bristle-grass Adherent Bristle-grass Adherent Bristle-grass Adherent Bristle-grass
Habit
Flower spike
Flower spikelets
Leaf ligule