Veronica is the largest genus in the flowering plant family Plantaginaceae, with about 500 species.

[2][3] Monophyly of the genus is supported by nuclear ribosomal internal transcribed spacer (ITS) and cpDNA.

[4] The taxa of the genus are herbaceous annuals or perennials, and also subshrubs, shrubs or small trees when Hebe is included.

[11] By the beginning of the 21st century, a range of genera were used for the "Hebe complex" consisting of Southern Hemisphere species related to Veronica, including Chionohebe, Derwentia, Detzneria, Hebe, Heliohebe, Leonohebe and Parahebe.

[13] As of October 2022[update], Plants of the World Online listed about 460 accepted species and hybrids in the genus Veronica.

Native Americans used Veronica species as an expectorant tea to alleviate bronchial congestion associated with asthma and allergies.

[21] An annual life cycle, and associated morphological traits, is an adaptation thought to have developed in response to an extremely arid or generally unpredictable environment, and may persist in Veronica due to a historic concentration and radiation of members of the genus in and from the climatically volatile Balkan Peninsula.