This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Shrubs, occasionally arborescent, or herbs, with angled or lobed leaves and axillary and solitary or clustered or terminal and racemose flowers. Very near Malva, but differing in having the three to six lobes of the involucel coherent about half-way up. Car-pels in a flattened whorl, indehiscent. About eighteen species, whereof one is Australian, two are from the Canaries, and the others from the Mediterranean countries. Named in honour of the brothers Lavater, Swiss physicians.
1. L. arborea. Tree Mallow. - A tall biennial species, softly pubescent all over. Leaves large, on long petioles, 5- to 9-lobed, cre-nate. Flowers purple, on short crowded axillary peduncles, about 2 inches across. This has a stout stem throwing off numerous lateral branches, and forms a very hand-some small tree. In rich soil in the South of England it often attains a height of 12 or 15 feet. It is occasionally met with on our coasts, but is generally considered to be an introduced plant.
2. L. trimestris (fig. 53). - A common annual species, about 3 feet high, with rosy pink or white solitary axillary flowers with a dark centre. A pretty plant where it has plenty of space, flowering freely for a longer period than many annuals. Spain.
Fig. 53. Lavatera trimestris. (1/3 nat. size.)