Mather Field Vernal Pools

Two-horned Downingia (Downingia bicornuta)
Brother Alfred Brousseau, © St. Mary's College

Photo by John Game
Toothed Downingia (Downingia cuspidata)
© John Game

Folded Downingia (Downingia ornatissima)
© John Game

	common name	Downingia

	scientific name	Downingia species

	family	Campanulaceae (bellflower)

	habitat	vernal pools

	size	Plants are 3 to 10 inches tall; each flower is 7 to 18 mm; Downingia bicornuta usually has larger flowers than the other two species.

	fun facts	Downingia are pollinated by native solitary bees. The bees collect pollen to feed their offspring.

	description	Member of the bellflower family. Each flower has five corolla lobes or petals. The two upper petals are smaller then the three lower. The flowers are mainly blue with white, yellow or other colors. Two-horned Downingia (top photo) has a pair of purple bumps near the center of the flower and the trigger hairs are long and twisted. Toothed Downingia (middle photo) has no dark spots and fang-like trigger hairs. Folded Downingia (bottom photo) has folded back upper petals with a small horn between them.

	life cycle	Downingia are annual plants. They germinate under water. When the pools dry in May, they bloom.

ecology

Downingia are endemic to vernal pools. In some pools, their synchronous mass bloom can look like a blue sky reflected off water. Each vernal pool will usually only contain one or two species of Downingia.

Downingia must cross-pollinate to produce seeds. To prevent accidental self-pollination, the flower matures in stages: It goes from being a male flower to being a female flower. When the flower is male, the solitary bee rubs against the trigger hairs to release pollen. When the solitary bee visits a female flower, the pollen is rubbed off onto the stigma to pollinate the flower.

investigate

Can you find examples of flowers in the male stage and the female stage? Clue: the female flowers have no trigger hairs and the stigma tip looks like a small round pillow.