Halimium lasianthum (Lam.) Spach
Cistus lasianthus Lam.
Eng.: Woolly rock rose. Spa.: Carpaza amarilla, carpazo, jaguarzo. Fre.: Hélianthème faux-alysson.
Shrub or subshrub, evergreen, hermaphrodite, up to 1.5(2) m in height, erect, highly ramose, light grey in appearance. Branches, branchlets and basal leaves covered with a dense whitish tomentum of stellate, velvety hairs. Leaves usually opposite, ± ovate, lanceolate or obovate, with entire margin, flat or slightly undulate; there are 2 types (dimorphic): leaves of sterile branches (usually the basal branches) are 0.4-4 × 0.2-1.6 cm, with short petiole, with clearly marked central vein on the underside, greyish-whitish on both sides because they are covered by a dense tomentum of stellate hairs (also with some simple hairs), persistent; leaves of floriferous branches (usually the upper branches) are more homogeneous in size (0.7-3.1 × 0.4-1.1 cm), sessile, with 3 clearly marked longitudinal veins, green because they are almost completely lacking of stellate hairs on the upper side (they only have them in the terminal part), covered with stellate hairs on the underside (they also have simple hairs on both sides). Inflorescence in relatively dense cymes, with short hirsute peduncles, with dense tomentum of stellate and applied hairs, mixed in with other simple solitary hairs or forming small fascicles. Flowers shortly pedicellate, in small groups of 1-5. Calyx with 3 sepals, 3.5-17 mm long, ovate, longly acute or even acuminate, with stellate hairs and simple unicellular hairs, solitary or fasciculate, mixed in with other multicellular, reddish and glanduliferous hairs. Corolla with 5 petals (7-20 mm long), yellow, usually with a brownish patch on the base. Fruit an ovoid capsule, 4-10 mm long, dehiscent in 3 valves, not visible because it is hidden inside the persistent calyx. Seeds (1-1.5 mm) polyhedral, with tuberculated surface and dark brown. 2n = 18.
Flowering:
February to May.
Fruiting:
May to September.
Habitat:
Clearings and edges of forests, mainly in pine and cork oak forests, as well as in the thickets resulting from their degradation; generally on siliceous, rocky or sandy terrain; from sea level to about 1,800 m in altitude. From subhumid to humid bioclimate.
Distribution:
Western portion of the Mediterranean (SW France, W Iberian Peninsula and NW Morocco). In Morocco it is found in the western Rif, basically in the cork oak forests or in its original area of distribution.
Observations:
Two subspecies have been described, subsp. lasianthum [H. formosum (Curtis) Willk.], from the sandy soils of the SW Iberian Peninsula and NW of Morocco; it is characterised by its pedicels with long simple hairs (1-3.5 mm) and sepals 7-17 mm with a very long and somewhat twisted apex. The other subspecies is H. lasianthum subsp. alyssoides (Lam.) Greuter [Cistus alyssoides Lam., H. alyssoides (Lam.) K.Koch.], of rocky or sandy soils, but always ± siliceous; it is found in the NW area of the Iberian Peninsula and SW France.
Conservation status:
A fairly rare species, that can become locally abundant. Currently, it has not been assessed at a global level in the IUCN Red List of Threatened Species.