Classical name probably of V. officinalis. The common name, from Celtic fer — to remove, faen — stone, refers to its use in the treatment of bladder stones.
Herbaceous annual and perennial herbs and subshrubs, spreading to erect, stems mostly square in section. Leaves opposite, decussate, occasionally in 3s, variously lobed, toothed and cut, stalked. Flower clusters mostly terminal, dense or open, branched, sometimes elongating. Calyx 5-ribbed and 5- toothed. Flowers regular or slightly 2-lipped, stalkless, salver-shaped, the tube straight or curved. Stamens 4, rarely 2, attached in the upper part of the tube. Ovary 4-chambered, with 1 ovule in each chamber. Fruit dry, enclosed in calyx, splitting into 4 nutlets.
Grown for the attractive, colourful flowers although several garden species have become environmental weeds of roadsides and waste ground and should be grown with caution. V. rigida Sprengel, Veined Verbena, from S America is a common coastal weed; it has stalkless, stem-clasping leaves.
Seed, cuttings and division.
Some species, especially V. officinalis, have medicinal properties; V. littoralis is used for fertility control in Uruguay.
Flowers stalkless; fruit splitting into 4 nutlets.
About 250 species, mostly from tropical and subtropical America.
Source: (2002). Verbenaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.