Images: ©Jouko Lehmuskallio
Yellow Rattle
Rhinanthus minor
- Family: Figwort Family – Scrophulariaceae
- Growing form: Annual herb. Hemiparasite.
- Height: 20–40 cm (8–16 in.). Stem erect, unbranched–sparsely branched, angular, brownish-red.
- Flower: Irregular (zygomorphic), 13–15 mm (0.5–0.6 in.) long. Corolla bilabiate with a long straight tube, deep yellow, hood-like upper lip with 2 violet teeth (max. 1 mm long), lower lip 3-lobed. Sepals 4, united, calyx laterally flattened, 10–12 mm long, dark, inflated. Flowers subtended by lanceolate, brownish-green bracts. Stamens 4. Pistil of 2 fused carpels. Flowers borne in short spike-like clusters at the end of the stems.
- Leaves: Opposite. Stalkless, lanceolate to narrowly elliptic, margins with blunt, shallow teeth. Central leaves with usu. max 10 pairs of veins.
- Fruit: A brown, flattened capsule (ca. 7 mm, 0.3 in.) enclosed within the calyx.
- Habitat: Roadsides, field margins, dry meadows, grassy slopes, pastures.
- Flowering time: June–July.
The yellow rattle absorbs additional nutrients from neighbouring plants. In Finland, the yellow rattle is an archaeophyte, which has found suitable habitats in dry meadows, pastures, and waysides.
The yellow rattle differs from its close relative, the narrow-leaved rattle (R. serotinus) by its flowers. The corolla-tube of the latter is curved upwards, and the teeth on the upper lip are 1.5 mm long.
