Marsh speedwell (Veronica scutellata)

Height: typically grows to a height of 0.5 to 2.5 meters (1.5 to 8 feet), with common ranges cited between 60 cm and 1.5 m (2-5 ft), though some specimens can reach over 2 meters (7 feet) tall. Its final height depends on growing conditions, but it's known as a tall, striking plant, particularly in its preferred open, disturbed environments.

Spread: spreads aggressively through wind-dispersed seeds with silky tufts and a deep network of underground rhizomes, allowing it to quickly colonize disturbed areas like recently burned or cleared land. A single plant can produce up to 80,000 seeds annually, which, combined with its ability to regrow from rhizomes after a fire, makes it a dominant pioneer species in landscapes.