Chiliadenus Cass.
Genus composed of 10 species, Mediterranean and Saharan-Arabian, of which 8 are found in North Africa, including 4 subshrubby species. C. iphinioides is described, the other are:
Ch. sericeus (Batt. & Trab.) Brullo [Varthemia sericea (Batt. & Trab.) Diels] is closely related to Ch. iphionoides. It differs by having leaves that are narrower at the base, not clasping, mucronate, and by clearly pedunculate capitula and obconic involucre with applied bracts, by its yellow flowers and slightly compressed achenes. It is endemic to the massifs of Ahaggar and Tassili n’Ajjer in the central Algerian Sahara and Libya (Cyrenaica).
Ch. candicans (Delile) Brullo [Varthemia candicans (Delile) Boiss.] (Ara.: Za’ter el-homar), it differs from Ch. iphionoides mainly by its velutinous indumentum and by its larger and linear lower leaves (30-40 mm). It is found in coastal dunes of Libya and Egypt, including the Sinai Peninsula and its distribution area extends to Syria.
Ch. montanus (Vahl) Brullo [Varthemia montana (Vahl) Boiss.] (Ara.: Heneida, neheida), differs from Ch. iphionoides by its larger size (sometimes exceeding 1 m in height), with less dense branching, by the yellowing of the indumentum due to the presence of abundant yellow glands, and by more opened inflorescences with larger capitula, with involucre about 12 mm long, with narrowly oblong bracts. It is found in desert areas of the Middle East, in rocky areas of deserts in the E of Egypt and the Sinai Peninsula.
Rare species with a small distribution area. Currently, they have not been assessed at a global level in the IUCN Red List of Threatened Species.
Key to species
1 Indumentum whitish, without yellow glands. Involucre 6-10 mm in length 2
1 Indumentum yellowish, with yellow glands. Involucre c. 12 mm in length Chiliadenus montanus
2 Lower leaves 30-40 mm, linear, velutinous Chiliadenus candicans
2 Lower leaves up to 15(20) mm, oblong or oblong-elliptical, sericeous or velutinous 3
3 Leaves narrowed at the base. Capitula pedunculate, with peduncle 5-10 mm. Involucral bracts with applied apex Chiliadenus sericeus
3 Leaves widened at the base, semiclasping. Capitula sessile or with peduncle up to 5 mm. Involucral bract with recurved apex Chiliadenus iphionoides
Updated by: B. Valdés.