Although winter is far from over here in Northeastern California, Leonard and I notice some vernal pools already forming. Vernal pools are seasonal bodies of water that usually form in the spring from winter rains and snow melt runoff. Vernal pools are typically dry for at least a part of the year. Certain flora and fauna have evolved to inhabit this form of wetland.
Although they will not emerge and flower until March or later, toothed downingia (Downingia cuspidata) are one of my favorite vernal pool flowers and I already look forward to their arrival. Toothed downingia grows in wet meadows or beside ponds and lakes as well as in vernal pools, but in vernal pools their synchronous blooms often form a carpet of flowers.
An annual native, toothed downingia is endemic to California (only grows in California). It is a small, tender plant, rarely growing more than 9 inches in height, usually much less. The branching stem is erect. Toothed downingia leaves are alternate, linear and sessile (no stems). The leaves become bract-like further up the stem.
Toothed downingia flowers are variable in color, ranging from purple to blue to almost white. There are 3 to 8 long, narrow, pointed sepals. The five petals are arranged into two lobes. The lower three petals are fused into a three-lobed lip. In the center of the lower lip are two touching yellow patches or one single yellow patch, outlined in white. The upper lobes are long and pointed. Toothed downingia flowers appear to have a pedicel (stem), but this “stem” is a long, inferior ovary.
Toothed downingia must cross pollinate to produce seeds. Solitary bees are the main agent of pollination. In order to prevent self-pollination, the flower matures in stages. The male stamen matures first followed by maturation of the female pistil.
Toothed calicoflower is another common name for D. cuspidata. Andrew Jackson Downing (1815 – 1852) is honored by the genus name, Downingia. The species name, cuspidata, means tipped with a point in Latin. The literature indicates this refers to the pointed leaves. I believe it may refer to the small point on each of the three lobes of the lower lip.
These toothed downingia were photographed in June along Lassen County (CA road 527, also known as Ash Valley Road.