Almost half of the Helianthemum species (Cistaceae) are found mainly in the
Mediterranean rim. Many of these species grow in regions with arid or semi-arid climates.
In the present work, five Helianthemum species [H. almeriense Pau, H. appeninum (L.)
Mill., H. cinereum (Cav.) Pers., H. hirtum (L.) Mill., and H. squamatum (L.) Dum. Cours.]
of the Iberian Peninsula were tested for germination. Two of them are Iberian endemic
shrubs: H. squamatum is an endemic shrub widely distributed on gypsum soils of semi-arid
Iberian Peninsula and H. almeriense is an endemic shrub of arid SE Spain.