Cerastium dubium (Bastard) Gupin

Doubtful Chickweed


CC = *
CW = 5
MOC = 6

© SRTurner

Family - Caryophyllaceae

Habit - Annual forb.

Stem - Ascending to nearly erect, sometimes sprawling with age, to 50 cm, often multiple from a cespitose base, glandular-pubescent.

Cerastium_dubium_stem.jpg Stems and nodes.

© SRTurner

Leaves - Opposite, entire, linear to narrowly lanceolate, sessile, to 3 cm, usually with glandular hairs.

Cerastium_dubium_leaf1.jpg Leaves adaxial.

© SRTurner

Cerastium_dubium_leaf2.jpg Leaf abaxial.

© DETenaglia

Inflorescence - Dichasial cymes, pubescent with short glandular hairs.

Cerastium_dubium_inflorescence.jpg Inflorescence.

© SRTurner

Cerastium_dubium_inflorescence2.jpg Flowers.

© SRTurner

Flowers - Bracts entirely herbaceous. Sepals 5-6 mm, glandular-pubescent, margins hyaline. Petals exceeding sepals, moderately deeply notched at tip, white. Stamens 10. Styles 3.

Cerastium_dubium_flowers.jpg Calyces.

© SRTurner

Cerastium_dubium_flower.jpg Flower.

© SRTurner

Fruit - Capsules straight, cylindrical, 8-11 mm, brown at maturity, dehiscing with 6 apical teeth.

Cerastium_dubium_fruit.jpg Fruit.

© SRTurner

Cerastium_dubium_fruit2.jpg Dehiscent fruit.

© SRTurner

Flowering - March - April.

Habitat - Crop fields, disturbed areas.

Lookalikes - Other species of Cerastium, and to a lesser extent, Stellaria.

Origin - Native to Europe.

Other info. - This species was first reported in the U.S. in 1966, in the state of Washington, and was first collected from Missouri in 2012. It is easily distinguished from other Missouri members of the genus, being showier and (usually) with flower centers appearing bright yellow from shed pollen. Additionally, leaves are very narrow and styles 3 in number instead of the usual 5. Dehiscent fruits have 6 apical teeth, rather than the 10 present in other members of the genus. The plant can form huge populations in alluvial farmland or other crop fields, which seems to be a preferred habitat.

Photographs taken near Labadie, Franklin County, MO, 3-31-2012, 4-12-2016, 4-25-2021, 4-9-2022, and 4-7-2023 (SRTurner).