- Name also: Longleaf Speedwell, Garden Speedwell
- Family: Plantain Family – Plantaginaceae
(formerly Figwort Family – Scrophulariaceae)
- Growing form: Perennial herb. Rootstock strong, oblique.
- Height: 30–90 cm (12–35 in.). Stem usually unbranched and glabrous, sometimes upper part branching and short-haired.
- Flower: Corolla almost regular (actinomorphic), purple–blue or occasionally white, 6–8 mm (0.24–0.32 in.) broad, fused, 4-lobed, wheel-shaped, with quite long tube (tube longer than broad). Calyx 4-lobed, lobes mainly hairy along edges. Stamens 2. Pistil a fused carpel. Inflorescence a very dense, spike-like, 10–30 cm (4–12 in.) long terminal raceme. Flower-stalk very short.
- Leaves: Opposite or whorled, short-stalked. Blade narrowly ovate–linear, margin densely and deeply serrated.
- Fruit: Obcordate capsule, with shallow notch, approx. 3 mm (0.12 in.) long, glabrous, brown.
- Habitat: By seas, lakes and rivers, coastal hedgerows, rocky outcrops by the shore, banks, commons. Sometimes an ornamental.
- Flowering time: July–August.
Long-leaved speedwell is a large, almost metre-long species which is an impressive sight when it flowers: almost a third of the plant can be comprised of its spike-like raceme. When you consider that it also flowers for a long time is no wonder that it is a popular garden ornamental. The species is also a popular plant among insects, especially bees and flower flies, but also swallowtail butterflies. In the wild it thrives in coastal areas: rocky and gravelly shores, waterside thickets, and sometimes also flood-influenced land next to both internal waters and the sea. Especially in northern Finland it can sometimes appear far from the closest shore on meadows or in a rocky crevice. These stands are probably a legacy of a time when the shore was a lot further inland than it is now.
Sharp-eyed observers can perceive small differences in the appearance of long-leaved speedwells that grow inland or by the sea, mainly with regards to the size and form of the leaves and how they are toothed. It is possible that inland plants are a stand of their own and those that grow by the sea are native to somewhere else around the Baltic, or else the coastal type has become different from the inland stand. In southernmost Finland the species can be mistaken for spiked speedwell (V. spicata). Long-leaved speedwell’s leaves are narrowly ovate, densely and deeply toothed, and glabrous or sparsely haired. Spiked speedwell’s leaves are narrowly elliptic, sparsely and shallowly toothed, and with short and glandular hairs. The species cross-breed sometimes when they grow next to each other.