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The Gesneriaceae family includes 150 genera, and has, in total, more than 3,200 species, distributed mainly in a subtropical, less often temperate climate. Most of them are perennials: grasses, vines, shrubs, shrubs, even small trees.
In indoor culture, the family is represented by abundantly flowering plants. The advantage of the Gesneriaceae is their great diversity (for example, dozens of varieties of Saintpaulias and Gloxinias have been bred and continue to appear); many of them are compact in size, which allows you to keep a whole collection at home, and also reproduce quite easily. An important advantage is that the Gesneriaceae easily overwinter in indoor conditions, if you provide them with enough light and protect them from hot dry air.
Gesneriaceae, according to the type of root system, are divided into three groups: plants with rhizomes, scaly rhizomes and tubers. Gesneriaceae, which have tubers, need a dormant period in winter, during which the tubers are stored in dry sand in a cool (but not cold) place. Rhizome Gesneriaceae can also have a pronounced dormant period, during which the rhizomes are stored in the sand, but occasionally moistened.
Another classification of the Gesneriaceae family is determined by the morphological and biogeographic differences of plants. The whole family is divided into two main subfamilies: the subfamily Cyrtandrods Cyrtandroideae (species native to the Old World - Europe, Asia and Africa) and the subfamily Gesneriaceae Gesnerioideae (species native to the New World - America), since 2008 the third subfamily has been assigned to the same family - Coronanteria Coronantherioideae, its few species are common in Australia and the Pacific Islands.
The family name was given in honor of Konrad Gessner - a Swiss physician, botanist, scientist who created the five-volume encyclopedia Historiae animalium (1551-1558), which formed the basis of modern zoology, and the first descriptions of flowering plants from the Gesneriaceae were also present here.
The appearance of representatives of Gesneriaceae is quite diverse: their stems can be erect, creeping, ampelous (hanging), leaves are almost always whole, in many genera and species on short petioles (petioles are shorter than leaves), opposite, sometimes in whorls, or spirally.
The flowers are bisexual, single or in loose inflorescences. The calyx consists of four to five sepals, green or colored, they are usually separate, sometimes fused into a tube. Corolla five-lobed, less often four-lobed, usually fused into a tube at the base. The tube may be flat like Saintpaulia's or elongated like Sinningia's Sinningia. Sometimes the corolla is two-lipped, consisting of upper and lower lobes of different sizes, as in Columnea Columnea. In most Gesneriaceae, flowers are adapted for pollination by insects or birds (hummingbirds), but some are capable of self-pollination (streptocarpus). The ovary is also upper in the Tsirtandrovs, in the Gesneriev subfamily it is usually semi-inferior or almost inferior. The fruit is a capsule, sometimes a berry. Seeds are numerous, small, with a straight embryo, with or without endosperm.
Most species of Gesneriaceae originate from humid tropical forests, where they grow in light partial shade of trees, where warm and humid air, some Gesneriaceae grow in the undergrowth along rivers, streams, waterfalls. Epiphytes grow on mossy tree trunks or damp rocky places where morning and evening fogs and periodic rains are frequent. Some species grow in areas with a pronounced alternation of dry and wet periods. In these cases, they have organs that store moisture - tubers (in sinningia) or scaly rhizomes (in coleria, gloxinia).
Certain conditions are necessary for the success of the culture of most Gesneriaceae.
- The warm content and the winter minimum for most of them are 17-18 ° C, but there are plants among them that need a winter temperature drop to 12-13 ° C for flowering (for example, streptocarpus).
- They require a place shaded from the hot spring and summer sun, the light should be bright and diffused. In winter, natural light may not be enough if the plant stands, for example, on the east or north window, while the rosettes of the leaves become loose, and the shoots are stretched out, the leaves sit on too long cuttings, the new leaves are small.
- Gesneriaceae love humid air, but it is not desirable for them to get water on the leaves. It is best to place plant pots on pallets of wet pebbles. You can spray, for example, on very hot days in summer, but only if the plant is in the shade, and using a very fine spray to humidify the air around the plants, and not spray the leaves themselves.
- Water the plants with warm or room temperature water, avoiding waterlogging or drying out of the earthy coma.
- For most gesneriaceae, a standard potting mix of 1 part light turf, 2 parts leafy soil and 1/2 part sand can be offered. In any case, the soil must be air and moisture permeable and have a slightly acidic reaction. For gesneria - epiphytes, it is very important to add disintegrants to the ground: vermiculite, coconut substrate (chopped coconut fiber or coconut chips), you can add finely broken pine bark, pieces of charcoal. Although there are also exceptions to this rule, for example, the three species of Ramonda Ramonda grow both in shady moist forests and in completely drying rocky gorges on limestone. At the same time, they have a feature rare for flowering plants (the so-called poikilogydria) - during the dry period, being in an almost air-dry state, literally a herbarium,after moistening, they resume their vital activity.
- Almost all Gesneriaceae do not like too large pots for planting, in such containers and after abundant watering, the roots easily rot.