Another “beach” wildflower photographed in May at Dry Lagoon Beach in Humboldt Lagoon State Park (Humboldt County CA) is the beach morning glory (Calystegia soldanella). A synonym for this member of the Morning Glory Family (Convolvulaceae) is Convolvulus soldanella. Other common names for this native perennial include seashore false bindweed and beach bindweed.
In North America beach morning glory is found along the Pacific Coast from British Columbia to Southern California and along the sea in Virginia and North Carolina. It also grows in temperate regions across the world. Beach morning glory habitat is coastal beaches and sand dunes.
Beach morning glory arises from deep rhizomes. The entire plant is hairless (glabrous) and is creeping or trailing. The fleshy stems produce a white latex.
The alternate beach morning glory leaves are thick and fleshy. Round at the tip and heart-shaped at the base, the kidney-shaped beach morning glory leaves are wider than they are long, measured along the midrib.
The flowers have a typical morning glory form – broadly funnel shaped with five wholly fused and pleated petals. The pinkish-purple flowers arise singly on stalks from the leaf axils. Five sepals and two bracts surround the petals and there are five stamens and a superior ovary.
Beach morning glory fruits are more or less spherical, two chambered capsules containing two to four large, smooth, dull black seeds.
The genus name, Calystegia, comes from the Greek – “kalux”/cup and “stegos”/covering or “a covering cup”. The reason for this name is unclear. Perhaps it refers to the cup-shaped covering the sepals and bracts form over the base of the petals. The diminutive of “soldo”, or coin, in Italian (soldanella) is the basis for the species designation and refers to the round leaves.