Cistus, with its many hybrids and cultivars, is commonly encountered as a garden flower. The common name rockrose is applied to the species, a name also shared by the related genera Halimium, Helianthemum and Tuberaria, all in the family Cistaceae. The common name gum cistus is applied to resin-bearing species, especially C. ladanifer.
Quasars are part of a class of objects known as active galactic nuclei (AGN). Other classes include Seyfert galaxies and blazars. All three require supermassive black holes to power them.
Most quasars have a very high redshift (the measurement of the stretching of light to the red end of the spectrum by the expansion of the universe). The implication of the large redshift is that quasars are very distant, meaning they are objects from much earlier in the universe's history.