Veronica catarractae, commonly known as Streamside Blue, Cascade Speedwell, or Waterfall Veronica, is a perennial herb native to the moist, riparian environments of New Zealand, including stream banks and the misty zones around waterfalls. It typically grows to a height of 0.5-1 feet (0.15-0.3 meters) and spreads 1-2 feet (0.3-0.6 meters) wide. This plant forms dense mats of foliage and produces striking blue flowers that are quite showy during its summer blooming period, adding a splash of color to garden settings.

Streamside Blue is valued for its ability to thrive in wet conditions and its ornamental flowers, which make it an excellent choice for water gardens, rain gardens, and areas near ponds or streams. It is also used in rock gardens and as ground cover due to its spreading habit. Gardeners appreciate its ease of maintenance and its tolerance of various soil types, including clay, loam, and sandy soils. While it prefers medium to wet soil conditions, it is adaptable and can tolerate drier soils once established. It is recommended to provide some shade in hotter climates to prevent scorching. Potential problems include root rot in overly saturated soils and susceptibility to slugs and snails. It is not known to be invasive outside its native range but should be monitored to ensure it does not outcompete native species in non-native environments.CC BY-SA 4.0