Laura McDermott, Senior Extension Associate
CCE ENYCHP
White Campion (Silene latifolia subsp. Alba), also known as White Cockle and incorrectly as Bladder Campion (Silene vulgaris), is an annual dioecious flowering plant native to most of Europe, Western Asia and Northern Africa and has become naturalized throughout North America with the greatest density found in north central and northeastern US and Canada. It is thought to have made its way to North America in ships’ ballasts. Interestingly, in England White Campion is known as the Grave Flower or Flower of the Dead as they can be found growing on gravesites and around tombstones. Some Native American people have used White Campion medicinally.
Description
White Campion is an annual to short-lived perennial or biennial. As White Campion is dioecious, meaning that it has male and female flowers borne on different plants, not all plants will have the distinctive. White Campion grows to 1.5-3 feet tall and bears fragrant tubular flowers that can be solitary on long flower stems or appear in clusters. The flowers have five white or pink petals that exceed the sepals. Petals are deeply notched with tiny ears on the sides. An identifying feature is the bladder like capsule just below the flower head. The small, rounded, rough seeds are produced in that bulb-like capsule. Female plants can produce 1,600 to 24,000 seeds per plant. Reproduction is primarily by seed.
The basal leaves with petiole (leaf ‘stem’) measure nearly 4 inches long by 1 inch wide. Leaves are opposite on the stem and as they go up the stem they get smaller in size with no petiole. The plant stems, leaves and seed capsules are hairy and the stems are jointed and can spread out in a bushy, almost prostrate habit or be very upright.
White Campion can be a serious problem in small grains, alfalfa, clover and specialty crops – specifically in perennial strawberry fields. The plant grows in grasslands cultivated fields, roadsides, pastures, and other disturbed soil sites as well as many undisturbed areas. It is most common on neutral to alkaline soils, but enjoys any sunny, well drained soil.
Management and Control
Cultivation or tillage during seedbed preparation will kill many white campion plants in the seedlilng stage. Well-established plants are usually not killed by tillage, and instead, tillage may promote seed germination. Establishing and maintaining competitive, desired vegetation is important for keeping this weed at bay. Campion seeds can contaminate alfalfa, clover, or grass seed, so purchasing quality, clean seed is important for preventing new infestations.
To control an established population, you should focus on stopping seed production. Hand-pulling, mowing, or herbicide applications are effective. Hand-pulling should be conducted in early summer when the soil is moist, and you are able to pull out the entire root. Mowing is best done between the times that the flower buds begin to form until the flowers begin to open.
Herbicides that contain dicamba or metsulfuron-methyl are effective on campion. Consult the product label for directions on application rate and timing.
White Campion is afflicted by the fungal pathogen Microbotryum violaceum, which acts as a sterilizing sexually transmitted infection in this species. Studies have also found that in nature, male White Campion can be impacted by inbreeding depression – pointing out why keeping new individual plants out of existing populations could be important. Anything to prevent hybrid vigor and further proliferation!
Resources:
Montana State University Extension, http://www.sarc.montana.edu/documents/weedposts/April%202018%20Weed%20Post_white%20and%20bladder%20campion.pdf
Wikipedia: https://en.wikipedia.org/wiki/Ojibwe
SEINet – https://swbiodiversity.org/seinet/taxa/index.php?taxon=18740&clid=67
GOBotany – https://gobotany.nativeplanttrust.org/species/silene/latifolia/