Yellowseed false pimpernel
Scientific Name: Lindernia dubia (L.) Pennell
Family: Linderniaceae
MORPHOLOGY
Growth and Size: An annual herbaceous plant, glabrous, ranging from 5 – 25 (40) cm in height.
Stems: Reddish-green stem, ± erect, sometimes decumbent, more branched in the upper part.
Leaves: Leaves sessile or with short petioles, decreasing upwards, with 7 veins and the central one more pronounced, opposite, ovate-oblong, attenuate at the base and ± acute at the apex, measuring 5 – 30 x 2.5 – 16 mm; margin crenate-denticulate due to the presence of 4-6 (10) teeth.
Flowers: Flowers positioned in the leaf axil with peduncles of 5 – 12 mm (shorter than the leaves in the lower part). Light green calyx, ± glabrous, with 5 linear teeth, 3 – 5 mm long, growing up to about 7 mm at fruiting. Lilac-colored corolla divided into 5 lobes of 5 – 6 mm; corolla tube narrow and bell-shaped ending with bilabiate limb; the upper lip ± erect with 2 small lobes, the lower one larger and three-lobed with dark veins. It blooms from June to September.
Fruits and Seeds: The fruit is a capsule about 4 x 8 mm, septicidal, subequal to the calyx, with a reduced style of 2 mm. Seeds with honeycomb-like head (with many hollows and depressions) measuring 0.3 – 0.4 mm.
DISTRIBUTION AND HABITAT
An invasive alien species present in northern-central Italy except Val d’Aosta, Liguria, Marche, and Abruzzi, as well as in Calabria, in rice fields and along watercourses and ponds, from 0 to 200 m.
Photo: Licensed for free use by iNaturalist and by Saxifraga and Jasenka Topic, Rutger Barendse.



















