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 with fleshy stems and leaves and scarious stipules. Leaves entire, flat or terete, the upper ones sometimes forming an involucre beneath the flowers. Sepals 2, cohering at the base in a tube adnate to the ovary. Petals 5. Stamens numerous, perigynous with the petals. Capsule membranaceous, half-inferior, the free part dehiscing transversely. Seeds numerous. There are sixteen species, all intertropical, and chiefly American. From porio, to bear, and lac, milk, referring to the milky juice.
1. P. grandiflora (fig. 51). - A very handsome annual when grown in light soil in a sunny situation. It has given birth to numerous varieties, some of which have been separated as distinct species. They are of the most brilliant shades of orange yellow, crimson, rose, or variegated and striped or spotted with two or more colours or shades, including white. There are double and single varieties. It includes Thellussoni, with scarlet flowers having a white centre; and splendens, with crimson or purple flowers. A native of South America, and rather tender.
Fig. 51. Portulaca grandiflora. (1/4 nat. size.)