Helichrysum Mill.

Genus composed of about 500 species, most of them from the Old World but reaching Australia in the SE. In North Africa it is represented by 6-10 species, mostly widely distributed in the Mediterranean region and Macaronesia. Although some species are hemicryptophytes slightly or not woody, such as H. lacteum Coss. & Durieu (incl. H. raynalianum Quézel) from Morocco, Algeria and Libya, or H. glumaceum DC. with the flower capitula long and narrow (1.5-2 × 2.5-5 mm), arranged in nearly all directions (not only upwards as in the rest of these species), with only 7-9 flowers and white involucral bracts, it grows mainly in the countries of the western Indian Ocean (East Africa and Arabian Peninsula) reaching the western Sahara through the Sahel. They are usually plants with stems woody at the base, then herbaceous, which rarely exceed 60 cm. Numerous species have been cited in North Africa, but recent studies have grouped most of the woody taxa in just 4 species. Here we will describe the most common, H. stoechas, the other 3 are:

H. italicum (Roth) G.Don is well differentiated by being an upright plant and well above ground (up to 0.8 cm), with longer leaves, 30-60 mm, cylindrical involucre only 2-4 mm wide, and bracts very imbricated, with outer bracts tougher, coriaceous. Species with great infraspecific variability. Currently species such as H. serotinum Boiss. & Reut. and H. picardii Boiss. & Reut., are included within this variability.

H. pendulum C.Presl. also presents subglobose involucres as in H. stoechas, but it differs from the above species by having a dense tomentum of white hairs covering stems and both sides of leaves, giving the plant a whitish appearance. It also has a great morphological complexity but since 2010 some authors (Crespo & Mateo) proposed to include 2 species present in North Africa (H. fontanesii Cambess. and H. boissieri Nyman) within the infraspecific variability of H. pendulum, which was subsequently confirmed by genetic studies (Herrando-Moraira et al., 2017).

H. orientale (L.) Vaill. is well differentiated by its whitish appearance, leaves from oblong-lanceolate to spatulate, flat, with margin not revolute and very prominent ligules (in other North African species ligules are hardly seen). Species from the eastern Mediterranean, from Greece to Egypt and littoral and sublittoral areas of Asia between Turkey and Palestine.

Species with diverse distribution areas although none of them seem threatened. Currently, none of them has been assessed at a global level in the IUCN Red List of Threatened Species.

Updated by: J. Charco & B. Valdés.