Hollyhock (Althaea rosea), a plant of the natural order Malvaceæ, commonly referred to the same genus with the Marsh Mallow (q.v.). It has a tall, straight, hairy stem; heart-shaped, crenate, wrinkled, five- to seven-angled leaves, and large axillary flowers almost without stalks; the leaves diminishing into bracts, and the upper part of the stem forming a spike; the petals hairy at the base. The hollyhock is a native of the Mediterranean, is to be seen in almost every garden in India, and has been much cultivated in gardens in Britain from a very early period. At present it is a favourite flower, and varieties, the result of cultivation, are very numerous. It varies much in the colour of the flowers, and double and semi- double varieties are common. It is an autumnal flower, continuing till the frost sets in. The plant is a biennial or perennial, but in the latter condition lasting only for three or four years in a healthy state. The stem rises to a height of 8-15 feet, unbranching, or nearly so. Since 1870-75 the plant has all but succumbed to what is known as the hollyhock disease, caused by a species of fungus (Puccinia) which attacks the leaves and finally proves fatal, unless prompt measures are adopted to arrest its progress. Sulphur dusted on the affected leaves has proved the most effectual cure. The fibres of the plant have been made into yarn, but it is not yet certain if it is really valuable for cultivation on this account, or for the manufacture of paper. It is not improbable that it might be cultivated with advantage to afford green fodder for cattle, which are very fond of its leaves, and the leaves are produced in great abundance if the plant is prevented from flowering. The flowers are mucilaginous and demilcent, and are sometimes used like those of mallows and marsh mallows. The leaves yield a fine blue dye.—The Chinese Hollyhock (A. chinensis) is an allied species.
