Saintpaulia is a plant genus that includes six species that belong to the family Gesneriaceae. The Saintpaulia ionantha species, or the African violet, is part of this genus. Most wild species have violet and blue flowers with the distinct Gesneriad family pattern of two upper lobes and three lower lobes. Modern hybrids have other colors, such as white, yellow, and red. These flowering plants are native to the rainforests of the Nguru Mountains in Tanzania and southeastern Kenya.
These herbaceous perennials can grow from 2 to 6 inches (5 to 15 cm) tall and 2 to 12 inches (5 to 30 cm) wide. Their hairy leaves are typically rounded to oval and 1 to 3 inches (2.5 to 9 cm) long. Five-lobed flowers that can bloom all year round grow out in clusters of three or more that are blue to violet. They may be given a rest from blooming by withholding water. The new hybrid plants produce single or double flowers with many different variegated or solid colors, such as pink, lavender, and cream.
The flowering plants of this genus are favored by some gardeners as potted houseplants. They may be propagated from seeds or leaf cuttings. The cut leaves with 0.8 to 2 inches (2 to 5 cm) of stalk are inserted into a potting mix or a compost mix. It generally takes 10 to 12 weeks before new leaves sprout.
In cultivation, Saintpaulia plants need a lot of care. Plenty of indirect sunlight, around 12 hours each day, can result in long-term flowering. These plants are best grown in soil-less potting mixes, but if using soil, one should keep it somewhat dry. Proper soil moisture balance is essential as these plants will rot with excess watering, but at the same time they are also sensitive to soil dryness and hardness. Watering is best done directly to the soil because water droplets will stain and destroy the leaves.
The genus is named after Baron Walter von Saint Paul-Illaire, who discovered them in 1892 when he was commissioner of Tanga, Tanzania. He sent seeds of the African violet, which he called the usambara violets, to his father in Germany. When the seeds reached Germany, the name was changed to Saintpaulia, which eventually became the genus under which the Saintpaulia ionantha or African violet was classified. As of 2010, there were more than 2,000 cultivars originating from species of the genus, but the majority of them originate from Saintpaulia ionantha.