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.
Herbs, rarely shrubby, stems often tumid at the joints. Leaves opposite or alternate, bistipulate, dentate, palmately or rarely pinnately lobed or dissected. Peduncles axillary, 1- or 2-flowered. Flowers regular. Sepals and petals imbricate in bud. Stamens usually 10, of which 5 are sometimes imperfect. Carpels 5, separating from the axis below and curled upwards; seeds 1 in each carpel. There are about 100 species, very widely distributed. About twelve are natives of Britain. G. Robertianum is perhaps the commonest. It is an erect foetid plant with reddish stems, much divided leaves, and small striped red flowers. The name is derived from yspavos, a crane, from the beak-like termination of the fruit - hence the English name, Cranesbill.
1.G. sanguineum. - An indigenous perennial species from 1 to 2 feet high. Stems geniculate. Leaves pilose, orbicular, 5- to 7-par-tite, lobes again divided into 3 or 5 narrow segments. Sepals awned. . Peduncles usually 1-flowered. Flowers about 1 1/2 inch in diameter, reddish purple. A very handsome species. There is also a distinct variety of more prostrate habit with pinkish flowers; it is the G. Lan-castriense of gardens.
2. G. platypetalum (fig. 57). - A Caucasian species. This is allied to sylvaticum, a handsome native species having clusters of purplish flowers. It is a very hairy plant, bearing a profusion of violet-blue flowers. This is sometimes grown under the name Ibericum, which is a very similar plant, and of which it may be a simple variety.
3. G. striatum. - A very com-mon species in cultivation. It usually grows about a foot high in compact tufts. Leaves 3- to 5-lobed; lobes toothed. Peduncles 2- or 3-flowered. Flowers white, striped with rose. A free-blooming species throughout the Summer. South of Europe.
Fig. 57. Geranium platypetalum. (1/4 nat. size.)
4. G. phoeum. - About 18 inches high and similar to G. pra-tense, with fewer smaller dusky dark purple flowers. Leaves on long petioles, orbicular or reniform, 5- to 7-lobed, lobes cut and serrate. Peduncles deflexed, 2-flowered. Central Europe; naturalised in some parts of England.
There are several other species in cultivation, including G. Endressii, with large rose-coloured flowers; G. pratense, a tall native species with deep blue flowers; and G. tuberosum, rose-coloured flowers.