
Due to the large size of the genus, authors have grouped species into several sections, each based on growth habit, flower and capsule form. Plants may vary from large, erect shrubs reaching 1.4 m, to dwarf, tufted and even mat-forming ground cover species. All plants possess mostly woody roots, which are situated very close to the soil surface. Branches are also woody and tough with short internodes that are often covered with dry leaves. There are some species that possess spines as protection against grazing animals. The flowers of Ruschia vary from white to pink and purple. They very much resemble another genus, Lampranthus, but the latter have much bigger flowers and more colour types. Members of Ruschia are all very floriferous; flowers literally cover the entire plant. Flowering takes place throughout the year, reaching a peak in the autumn and spring. Flowers are diurnal (opening during the day) and sweet scented; the leaves are often bluish green, three-sided, sometimes with teeth along the edges, and are nearly always stippled with darker transparent dots, which is an interesting feature in the genus.
The fruits are capsules, which have 5 or rarely 6 locules (chambers), a deep capsule base, and no valve wings. Seeds are yellowish to brownish, 0.5 to 1 mm in diameter, more or less flat and spherical. All plants in this genus are generally fast-growing but short-lived and becoming stocky after four years, especially in arid and semi-arid areas.
Only about six species in the genus are listed as threatened (Hilton-Taylor 1996). These are: R. amicorum which is listed as rare and occurs in the Cape Floristic Region (CFR); R. filamentosa, another CFR species which is listed as an I (intermediate) i.e. extinct, endangered, vulnerable or rare - the information seems to be insufficient to decide in which category it must go; R. lawsonii, also listed as K, suspected to be in one of the mentioned categories (R. lawsonii is now in the genus Antimima ); R. leipoldtii which is endangered (also in the genus Antimima ); R. promontorii which is endangered and from the CFR; and R. rubricaulis which is an intermediate species from the CFR.
Threats to these species occur mainly as a result of agricultural activities such as unwise grazing practices, or clearing of habitat for agriculture (Chesselet & Smith 2002 ). Species identified as rare are almost always targeted for cultivation in ex-situ conservation projects. These projects form part of a national Threatened Species Program (TSP) currently in operation in all of the eight national botanic gardens of South Africa. The aim is to build up well-represented collections of all threatened taxa that will eventually be used to strengthen wild populations.
Species of Ruschia shows remarkable variability as a result of the different habitats in which they are found. Soil types vary from quartzitic sandstone, calcareous soils, decomposed shale, clay soil, and deep sandy loams. Plants are found in the fynbos, strandveld, renosterveld, grassland, Namaqualand karoo, succulent karoo, savanna and bushveld biomes of South Africa. Geographically their distribution stretches from as far as Windhoek in Namibia to the Western Cape, Eastern Cape, Free State and Gauteng. The highest frequency, however, is found in the drier southwestern region near sea level, with less than 100 mm of annual winter rain. This is significantly different to the other members of the genus occurring in summer rainfall regions that receive up to 800 mm per annum. Ruschia are tolerant of frost, fires and extreme droughts, and this, together with their vibrant colours, make them among the most popular water-wise garden plants known today.
View source for more information: http://pza.sanbi.org/ruschia