Gesneriaceae - Gesneriads
The Gesneriaceae is a family of 150 genera and around 3200 species of tropical dicotyledenous flowering herbs, shrubs and trees with a few temperate species.
The irregular flowers have five sepals and five petals which may be joined at their base to form a tube. Leaves and flowers may be softly hairy and are mostly opposite or whorled, but can be alternate. The ovary can be either inferior or superior and usually forms a rounded or ovate capsule contaiing numerous seeds, although some species bear berries. All Gesneriads have fibrous roots, but some also have tubers or rhizomes as storage organs and some species have aerial stolons. Many species grow naturally as epiphytes or in depressions and crevices on rocks.
The Gesneriad Family includes many popular houseplants with a degree of succulence from the genera Aeschynanthus, Columnea, Gloxinia, Nematanthus, Saintpaulia and Streptocarpus.
Many hybrids and selected cultivars are available. These plants are not xerophytic and require regular watering and frost-free conditions, but most are undemanding.
The Gesneriad Society maintains a register of Gesneriad hybrids.
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Aeschynanthus Jack, 1823 (Lipstick Plant)
is a genus of about 140 trailing plants or small shrubs with epiphytic and climbing habits, found in India to South-East Asia and the Borneo archipelligo. Leaves are opposite and fleshy or leathery or in some species quite soft and non-succulent. Leaves and stems may be slightly pubescent. Flowers are generally red and attractive to sunbirds. Aeschynanthus are free-flowering plants, suitable for hanging baskets.
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Left: Aeschynanthus pulcher from Malaysia is a showy plant for a hanging basket. Plants are propagated from stem cuttings, typically rooting at leaf nodes and easily rooted in a glass of water.
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Left: Aeschynanthus radicans is an epiphytic vining plant from Malaysia and Java. The leathery green leaves offset the tubular, scarlet flowers. All parts are slightly pubescent. Pruning the stems emcourages new growth. This species is popular as a conservatory plant and for hanging baskets. It appreciates humidity and bright light, although not full sun. An open potting mixture with added sphagnum moss or bark simulates their natural habitat.
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Columnea Linnaeus, 1753
Named for: Fabio Colonna 1567-1640, Italian botanist.
is a genus of about 70 trailing plants or small shrubs from the Carribean, Mexico and South America to Ecuador. Columnea are free-flowering plants, suitable for a bright window ledge and hanging baskets although full sun is best avoided. As with other succulent plants, avoid over-watering. They are propagated from stem cuttings.
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Left: Columnea linearis from Costa Rica is a training sub-shrub with opposite lanceolate leaves whose upper surface bears a longitudinal groove. The pink to purple tubular flowers are carried erect. The seeds are within pale pink berries.
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Nematanthus Schrader 1821
is a genus of about 30 trailing or climbing sub-shrubs from tropical South America. They are often called "goldfish" plants or "clog plants", referring to the shape of the flowers in shades of red, orange and yellow. The flowers are attractive to humming birds. The trailing foliage of some species makes them suitable subjects for hanging baskets, but others form small shrubs with a woody base.
Nematanthus are tolerant plants for a bright window ledge although full sun is best avoided. As with other succulent plants, avoid over-watering. In their habitat they are often epiphytic and a porous open medium suits them in cultivation. A long day length promotes flowering so they generally flower during the summer, unless day length is prolonged under artificial lights. Propagate from stem cuttings.
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Left: Nematanthus strigillosus is a trailing plant, with small orange flowers in the classic "goldfish" shape. Suitable for a hanging basket.
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Left: Nematanthus tropicana (N. perianthomegus x N. radicans) is one of many easily-grown Nematanthus hybrids, with dark green glossy leaves and a sub-shrub habit. Clusters of red and gold candy-striped blooms are produced quite freely.
Photo: Arkadiusz Bajur
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Saintpaulia Wendland 1893 (African violets)
named for Baron Walter von Saint Paul-Illaire (1860-1910)
are popular undemanding flowering plants with quite fleshy leaves and leaf stems. Leaf margins, stems and even the leaf surface are often pubescent. Flowers are produced in various shades of purple through pink to white. The potting mixture should be allowed to dry out between waterings. A new plant can be propagated from a single leaf with its stem, which should be buried in potting mix to the point where the stem joins the leaf base.
Numerous cultivars and hybrids are available in a wide range of colours including shades of maroon, purple, blue and white and variegated petals. Only yellow flowers have so far eluded the plant breeder. Double flowers are a recent innovation.
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Saintpaulia ionantha var. ionantha |
Sinningia Nees 1825
a group of about 60 herbaceous plants, most with large globular tubers. Many species originate in Brazil but others are distributed across South America from Argentina to Mexico. Sinningia speciosa is commonly sold as a Gloxinia.
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Sinningia leucotricha Hoehne 1956. Syn. Rechsteineria leucotricha
(Cardinal flower, Brazillian Edelweiss)
from Brazil, is the most widely grown truly succulent Gesneriad, a tuberous plant producing simple branches that bear a cluster of leaves covered in silvery-white hairs. In the Spring, orange to red tubular flowers are produced in the centre of the leaf clusters.
The tuber should be planted on the surface as a caudiciform and can get quite large (10in). It is possible to propagate the plant by dividing the tuber. As the tuber acts as a storage organ, this plant tolerates a surprising amount of neglect. Reduce water during winter dormancy.
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Families of Succulent Plants 
