Alopecurus geniculatus

Water Foxtail


Field view of Alopecurus geniculatus or Water Foxtail

Field view of Alopecurus geniculatus, common name Water Foxtail. It has short 1/8th-inch awns.

 Water Foxtail Inflorescence

The seedhead is what I call a puff, an awned puff, and quite short, normally about 1.5 to 2 inches.

 Showing Short Awns

Awns are very short. Like most "puffs," the seedhead completely conceals the stem (rachis).
Short Seedheads of Water Foxtail

The longest of these seedheads is less than 3 inches (squares are 1/4 inch).

 Close View of Seedheads

Even in this close view you can barely make out the awns.

 Visible Short Awns

The pattern of spikelets is distinctive as are the short awns.
Micro View of Spikelets

These tiny spikelets are quite diagnostic with their bent awns and hairy sides.

 Close View of Spikelet

An even closer view shows the hairs better.

 Roots of Water Foxtail

Perennial grasses like Water Foxtail have relatively deep and thick roots, so they are much harder than annuals to pull or dig up.

How to Identify Water Foxtail

  This is a short puffy grass with very short, bent awns. The plant itself is often very short, under one foot, but can grow knee-high or more with plenty of water. To see the bent awns you might have to pull apart some of the seedhead.


Similar Species

  There are quite a few puffy grasses in Arizona with rather short seedheads such as Water Foxtail, which is awned. Alopecurus aequalis (Shortawn Foxtail) has short awns or none.