This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
A large genus of hardy and half-hardy herbaceous and shrubby plants differing greatly in appearance and habit. Among the best of the herbaceous group are gentianoides, 1½ ft., porcelain blue, with a white-flowered variety (alba), and one with variegated leaves; incana (or Candida), dark blue or purple, with silvery leaves, often used for carpet bedding; longifolia, 2-4 ft. lilac, white, rose, or purple, often confused with spicata, a British plant, 6-18 in. high, with spikes of bright-blue flowers (fig. 252). There are several varieties of spicata, such as alba, white; nana, 6-9 in. high; rosea, pink; and a form with variegated leaves. V. Teucrium, 9-12 in., decumbent, pale or deep blue; the variety prostrata or rupestris is a very useful edging plant with masses of deep-blue flowers or white in the form alba; V. pectinata and V. repens are also trailing species with bright-green leaves and pale-blue flowers. V. virginica (Culver's Physic) is a noble plant, 2-6 ft. high, with long spikes of blue flowers - white in the variety alba.
Fig. 252. - Veronica spicata.