Flower:

One or more elongating spike-like racemes up to 12 inches long at the top of the stem, with flowers blooming from the bottom of the cluster up. Flowers are short-stalked, about ¼ inch (5 to 7 mm) across, have 4 lobes nearly equal in size and shape, a tube about as long as the lobes, and 2 long stamens and a single long style projecting from the tube. Color is blue to purple, occasionally white. The green calyx surrounding the base of the flower is shorter than the floral tube and has 4 pointed lobes. The calyx and flower stalks are minutely hairy.

Leaves and stems:

Leaves are opposite or whorled in 3s, 3 to 5 inches (8 to 12+ cm) long, up to about 1 inch (1 to 3+ cm) wide, narrowly egg-shaped to lance-linear, pointed at the tip, on a short stalk. Edges are sharply toothed, surfaces sparsely hairy to nearly hairless. Stems are erect, short-hairy on the upper plant, and usually unbranched. Colonies or clumps form from creeping, horizontal stems (stolons).

Fruit:

Fruit is an oval to somewhat heart-shaped capsule 2 to 4 mm long, slightly flattened, shallowly notched at the tip, with the remains of the style persisting at the tip. Inside are up to 40 light brown seeds.

Notes:

Long-leaved Speedwell is an attractive ornamental introduced from Europe that occasionally escapes cultivation. It has not been recorded often in Minnesota, though, like most weeds, is also likely under-reported. According to the Invasive Plant Atlas, West Virginia designated it invasive, so beware. In its native range it's usually found in rock outcrops or in moist, rocky or gravelly soils near seas, lakes and rivers, while in North America it can become established outside garden settings in a variety of habitats such as road ditches, fields, waste places and open woods. There is a white form that could mistaken for Culver's Root (Veronicastrum virginicum), which is typically a taller plant with leaves always whorled, usually in 4s or 5s.