Dayflower - Commelina erecta

Spiderwort Family (Commelinacae)

Considerations: From the information in Southwestern and Texas wildflowers, the specimen on the right could be the Whitemouth Dayflower. It is hard to say without more photographs and a better examination.

Stems: Jointed.
Leaves: Thick, succulent, grasslike in shape, sheathing at the base.
Flowers: 3 sepals, 3 petals, and 3-6 stamens. Grow in clusters.

"They wither within a day or less, others taking their place over a long blooming season. If they are picked, the petals quickly become pulpy or liquid; hence, they are sometimes known as Job's tears or widow's tears" [Loughmiller].

Petals: Lower petal is white, very small and apt to be overlooked.
Bloom Period: May to October.

Sources:
Loughmiller. Texas wildflowers.
Niehaus. Southwestern and Texas wildflowers.
Photo: Courtesy of S. Peregrine Johnson