Proteas are a family of shrubs with unusual and beautiful flowers. Most South African Proteaceae occur in the Cape, hugging the coast and mountainous regions eastwards to Port Elizabeth and spreading up the west coast to Vanrhynsdorp. The genera concerned are Aulax, Leucadendron, Paranomus, Serruria,Faurea, Sorocephalus, Spatalla, Protea, Diastella, Mimetes, Orothamnus, Leucospermum, Brabejum and Vexatorella.
Proteas are a part of fynbos, and grow in variable soils that are generally poor with a predominance of Table Mountain sandstone, particularly in the mountainous regions.
Proteas also grow in Bokkeveld shale which has a high content of clay. Some even grow in the other extreme of virtually pure sand, particularly along our coastal regions. The pH of the soils is on the acid side although there are some areas with alkaline soils with pH as high as 8,0.
The Cape flora thrives under highly variable climatic conditions. A maximum temperature of 32oC is not uncommon during the summer months, particularly in the regions of the Sandveld and Cederberg. The mountain ranges are cooler, experiencing the effects of prevailing winds, mists and cloud. The minimum temperatures occasionally fall below 0oC in many of these areas although not for long periods of time. Snow falls regularly in the Cape mountains each winter.
Protea occur in regions where the rainfall varies from as low as 180mm to 2500mm per annum, but many species occur in depressions, gullies, valleys and on south-facing slopes where the plants use underground moisture accumulated during the winter months. Protea cynaroides is a good example of this. It grows in areas with abundant underground seepage but with annual rainfall that varies from 300 mm to 1500 mm.
An important factor in the ecology of Proteaceae is a well-drained soil and efficient drainage system. This provides not only a well-aerated soil, but also a cool root system which is important.
The Proteaceae are essentially social plants, although there are a number of exceptions. Many of the species growing in their natural habitat occur in close proximity to one another, forming close-knit communities.
The individual plants protect one another from prevailing winds. They create a dense cover which prevents compaction, keeps the soil cool and reduces the rate of evaporation.