Habitat: Southern Africa, savannah, succulent Karoo
Cultivation: Water carefully, Exposure to direct sunlight, substrate well-draining,
Curiosity: Ruschia’s seed capsules are hygrochastic, that is to say that they have triangular valves that open and close with humidity variations.
Ruschia is a genus of plants that belongs to the Aizoaceae family, native to the driest environments of southern Africa.
It is a very wide genus and includes many species, with very different aspect and size, so that botanists have grouped them in several sections.
In general, these plants have woody and superficial roots. They can appear as shrubs of a maximum height of 1.5 meters or as dwarf plants that develop in “tufts” or become upholstered and form mats.
Their stems are succulent or sometimes woody. If succulent, they are bluish-green. The leaves, also bluish-green, are usually tetrahedral in shape, reduced or transformed into thorns in some species. This is to minimize the evaporation of water from the leaves and thus survive in their extreme environments, characterized by long dry periods, high temperatures and extreme intensity of sunlight.
Actually we shouldn’t imagine the stems and leaves of Ruschia as a common stems and leaves.
The stems of many Ruschia, in fact, are composed of pairs of leaves that follow one another as in a chain, in which each pair of leaves blooms from the other, in particular from a bud between the two leaves of each couple. In this way, a fascinating modular alternating cross-shaped structure is formed, in which the pairs of leaves are always rotated 90ºC one after the other, so that no leaf covers the one below.
In addition to this singular habit, Ruschias are also appreciated for their beautiful and abundant blooms, which often cover the entire plant! Moreover, the flowering is continuous and can be observed almost all year round, with more intense periods in Autumn and Spring. The flowers are of different colors depending on the species, very fragrant, diurnal (i.e. they open during the day).
In their natural environment, these fragrant flowers are source of nectar for many different species of pollinating insects, including different types of flies, butterflies and bees. Thornless Ruschias are among the favorite dishes of many antelopes in the area.
Ruschia are native to South Africa and Namibia. In particular, they are present in Savannah environments, from the Succulent Karoo, a semi-arid ecoregion with one of the most important succulent biodiversity in the world, to the Namaqualand karoo, another region rich in biodiversity, to other characteristic ecosystems present only in South Africa including fymbo, renosterveld, bushveld. Many species of Ruschia can be found especially in very dry areas, with average rainfall less than 100 millimeters per year! This means that these species live in environments where it rains on average little more than in the Sahara desert!
The habitat of Ruschias is very diverse: that’s why they have in fact differentiated in many species, adapting to many different environments. The preferred soils go from quartzitic sandstones, calcareous soils, soils originated by the decomposition of schistose rocks, clay soils, or deep alluvial and sandy soils. Practically all types of soils!
TIPS FOR GROWING
Growing indications can change a bit from species to species as Ruschia is a very large and diverse genus, but there are many common points between the different species.
- Ruschias love direct light all year round and should be watered carefully, especially during rainy winters in temperate climates.
- In winter, under particularly humid and cold conditions, they should be covered with plastic, if placed outside, and watered rarely: only when you notice signs of withering or in any case never more than once every 1-2 weeks. Between Spring and Autumn it should be watered regularly. Don’t worry if you once forget to water it: your Ruschia is very resistant and is used to drought
- The growing substrate must be generally well draining, equipped with a good sandy or rocky component: a cactus mix will do well.
- They tolerate both high and low temperatures, if it’s not humid and cold. In humid climates, promoting ventilation will benefit your Ruschia.
The propagation of Ruschias is generally done by cutting. The cuttings should be planted in a cactus mix, in a position sheltered from the wind but bright, and watered every day with a little water to keep the soil moist until rooting, which generally takes about a month.