This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
Geranium striatum, L. (= G. versicolor, L.). - ■ This is a colonist and a garden escape in shrubberies, or found on roadsides, etc, being rare. The stem is hairy, erect. The petals are white with purple veins, and the flower-stalks are 2-flowered. It resembles G. nodosum, L. The plant is 1-2 ft. high, flowering in July and August, and is a herbaceous perennial.
The habitat of this plant is waste places. The habit is prostrate. The stem is stout, hairy, with spreading hairs. The leaves are pinnate, with ovate, coarsely unequally toothed, nearly stalkless segments, with deep, sharp, irregular teeth. The stipules are broadly ovate, blunt. The flowers are bluish-purple or pale rose, numerous on each stalk. The perfect stamens are toothed below, without hairs. The carpels are hairy, with a glandular depression and a concentric furrow below it. The beak is downy. The plant is 4 in. to 2 ft. high, flowering between June and August, and is a herbaceous annual.