Thulin, M. (1993) Cistaceae in Flora of Somalia 1: 207-208
Plants herbs or shrubs, often with stellate indumentum, sometimes with simple hairs. Leaves usually opposite, rarely alternate, stipules present or absent. Inforescences of solitary flowers or cymes. Flowers bisexual, radially symmetric. Sepals 3 or 5, often unequal; petals usually 5, rarely 3 or absent, twisted or imbricate, usually soon falling; stamens many, free; ovaries superior, 1-celled or incompletely septate and with parietal placentas; styles simple or absent. Fruits capsules opening by valves from the top downwards; seeds with endosperm, embryo more of less curved.
The family Cistaceae includes seven genera and about 175 species. Almost all the species are native to the northern hemisphere, primarily in the Mediterranean region.
Only one genus is known from Somaliland, Helianthemum. All three species in the Flora of Somalia are known only from reegion N2, which comprises the eastern part os Somaliland.