Dark-tip Bird’s Beak

Dark-tip bird’s beak (Cordylanthus rigidus) is an airy, green and/or burgundy colored plant that is easily overlooked. The strange flowers occur in small, terminal clusters, surrounded by bristly specialized leaves. If viewed from the right angle, a flower looks like a tiny bird’s beak, giving the plant its name. The entire cluster has been likened to a spider’s egg sac.

Dark-tip bird’s beak is a partial parasite. Their roots penetrate the roots of surrounding plants and obtain nutrients from them.

Description ^4,11,23,59

Dark-tip bird’s beak is a lacy, almost ethereal  annual plant, usually less than 3 feet (1 m) in height. Reddish stems are upright and loosely branched. Leaves are usually divided into three thread-like lobes, up to 1 1/2 inches long (4 cm) long. Foliage may be green or burgundy or a combination of the two. Long, stiff bristles cover the leaves and flower bracts; when backlit these shine, giving the plant a halo.

Flowers are born in spherical clusters, up to 1 1/2 inches (4 cm) across. Flowers are white and 1/2 to 3/4 inches long, two-lipped and strongly flattened between two leaf-like straps, one of which is the calyx, the other a specialized floral bract. The upper lip of the flower encloses a pistil and four unequal stamens, each with two anthers. A dark burgundy spot is concealed within the lower lip of the flower. Flower, calyx and floral bract are loosely enclosed within bristly outer bracts, which usually have three linear lobes that may be tipped with burgundy.

The structure of the flower and subtending bracts is complicated, but the inflorescence is unmistakable – a case where a picture is worth a thousand words. A detailed verbal description is given by Prigge and Gibson,⁴ and individual elements are pictured by Valois.³ To some the flower resembles a bird’s beak. To others, it looks like the egg sac of a spider.¹⁰⁰ The blooms occur mainly June to September.¹

Twenty to twenty five tiny seeds, develop in a two-chambered capsule, less than 1/2 inch (1.1 cm) long, which splits open longitudinally to release the seeds.

Classification ²

Dark-tip bird’s beak is a dicot angiosperm in the broomrape family (Orobanchaceae). Plants in this family have bisexual, strongly bilateral flowers. Many genera in the broomrape family were formerly placed in the figwort family (Scrophulariaceae), but all are distinguished from other figwort genera by being totally or partially parasitic.¹⁴³  The broomrape family includes serious agricultural parasites¹⁸⁵ as well as some of our most unusual wildflowers, such as bird’s-beak, Indian paintbrush and owl’s clover.

There are four subspecies of C. rigidus in California.^2,7 The subspecies in the Reserve is ssp. setiger, which is distinguished by the middle lobe of the outer flower bract which is expanded at the end and often burgundy tipped.

Note: The subspecies name, setigerus, seems to dominate setiger in the literature.^1,4,8,59 Jepson² uses setiger and Cal Flora⁷ lists both without comment, but link them both to ssp. setiger in the Jepson eFlora. Following our policy to accept Jepson as our standard, we have used setiger.

Ecology ⁵⁹

Dark-tip bird’s beak is a partial parasite (hemiparasite). Although the leaves contain chlorophyll and the plant can make its own food, the roots often penetrate the roots of nearby plants, stealing nutrients and water from them.  Most hemiparasites can live independently, but the plants are smaller than when they live partly as a parasite.¹⁸⁶

Human Uses ¹⁷

The Luiseño, near Oceanside, used dark-tip birds beak as an emetic.

Interesting Facts

Visit dark-tip bird’s beak on a warm sunny day and you will probably be joined by bumble bees. Bird’s beak is pollinated by bumble bees and possibly by hummingbirds attracted to the nectar. Smaller insects may lack strength to open narrow-mouthed flowers.⁵⁹

The common name comes from the resemblance of the flower to a bird’s beak. This similarity is enhanced by gently compressing the petals laterally, which opens the beak like a baby bird begging for a worm.