T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Veronica anagallis-aquatica (Blue Water Speedwell)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Asterids 
Order: Lamiales 
Family: Plantaginaceae
Genus: Veronica 
Species: V. anagallis-aquatica
Binomial name: Veronica anagallis-aquatica 
Synonyms: Veronica anagallis, V. catenata, V. comosa, V. connata, V. glandifera, V. grandiflora, V. × lackschewitzii, V. micromeria, V. salina
Common names: Blue speedwell, Blue Water Speedwell, Water speedwell, Sessile Water-speedwell, Brook-pimpernell

Veronica anagallis-aquatica is a species of flowering plant in the plantain family. Its true native range is not clear, but the plant is present on most continents, and in most places it is probably naturalized.
It occurs in many types of moist and wet habitat, and it is semi-aquatic, often growing in shallow water along stream banks, in ponds, and in other wetland environments. It is a rhizomatous perennial herb with stems growing 10 centimetres to about a meter in maximum length. It may be decumbent, the stem spreading along the ground and rooting where it touches moist substrate, or erect in form. 
The oppositely arranged leaves are green, smooth-edged or toothed, and sometimes clasping the stem where the leaf pairs meet at the bases.
The inflorescence is a raceme of many pale violet-blue flowers arising from the leaf axils. Each flower is borne on a short, curving pedicel. The flower corolla is up to a centimetre wide with four lobes, the upper lobe being widest. The individual flowers are 6 mm wide and have 4 purple-streaked lobes with white at the base, 2 stamens, and 1 stigma. The flowering season is Spring-Summer.

On roadside drain.

The underside of a leaf.

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/