Images: ©Jouko Lehmuskallio
Common Cow-wheat
Melampyrum pratense
- Family: Figwort Family – Scrophulariaceae
- Growing form: Annual herb. Hemiparasite.
- Height: 10–40 cm (4–16 in.). Varyingly branched.
- Flower: Irregular (zygomorphic), 10–18 mm (0.4–0.7 in.) long. Petals 4, united, corolla bilabiate, pale, bright, or deep yellow or red-tinged, with long, usually whitish tube, and straight lower lip. Sepals 4, united, calyx-lobes long, curved to the same direction. Stamens 4. Pistil of 2 fused carpels. Flowers in pairs in the axils of bracts, on one side of the stem. Upper flowers with toothed to lobed subtending bracts.
- Leaves: Opposite. Generally unstalked, narrowly elliptic to almost linear. Subtending bracts of lower flowers with entire margins, those of upper flowers usu. basally toothed or with long slender lobes.
- Fruit: A capsule, ca. twice the length of the calyx.
- Habitat: Dryish and damp coniferous forests, also rock outcrops, bog hummocks, and lower parts of the alpine tundra.
- Flowering time: June–August.
The common cow-wheat is the most common species of cow-wheats in Finland. It has spread here already in the late stages of the ice age. It is a variable species, which suggests that populations with e.g. different prevailing flower size have arrived at different times. The common cow-wheat is a varyingly branched annual that often turns blackish on drying. It is a hemiparasite which means that it absorbs additional nutrients from neighbouring plants.
The seeds of the common cow-wheat germinate in the autumn. The seedlings overwinter and recommence growth in the following spring. Thus, the species is an autumn-germinating or overwintering annual.
