Foothills. Roadsides, fields, lawns. Spring.
Near Yellowjacket Canyon, April 21, 2010.

Ulmus pumila flowers are minute and packed into tight birdnest clusters.

Each of the two clusters at left is about seven millimeters wide and three millimeters high on last years stem growth of about two millimeters in diameter.

Numerous clusters are scattered over the latest few feet of growth of most branches of U. pumila. Seed production is, therefore, monumental and since seeds readily germinate in any relatively moist areas (gardens, flower beds, house foundations, and roadsides), this non-native is a dominant tree in both towns and country-side in the Four Corners.

Foothills. Roadsides, fields, lawns. Spring.
Near Yellowjacket Canyon, April 20, 2010.

The styles (female) are green, split into two parts, and fringed.  Anthers are red-brown.  The flowers are enclosed in papery tan coverings with reddish tops and about a dozen of these are bundled in one cluster in the photograph at left.

Foothills. Roadsides, fields, lawns. Spring.
Near Yellowjacket Canyon, April 20, 2010.

Foothills. Roadsides, fields, lawns. Spring.
Near Yellowjacket Canyon, April 21, 2010.

Foothills. Roadsides, fields, lawns. Spring.
Near Yellowjacket Canyon, June 7, 2010.

Just as leaves begin to show (about six weeks after flowers are fertilized), seeds ripen and fall to the ground in massive numbers.  If seeds fall in dry areas they have little chance of germinating, but if they fall in moist areas, such as, gardens, around house foundations, and roadsides they can sprout and grow quickly.