Chamaephytic, glabrous, nonglutinose subshrubs or suffrutescent herbs, with erect branches. Leaves (on lateral branches) sessile, narrowly pinnatisect. Cephalioids well differentiated, involucral bracts and receptacle bracts clearly distinct from leaves. Main central cephalioid similar in structure to lateral ones. Involucre with fused, cup-shaped base and distant, free,
slender, subulate lobes. Peripheral receptacle bracts similar and transitional with involucre lobes, inner receptacle bracts narrowly lanceolate, free. Receptacle lens-shaped. Cymose groups many, 2- or 3-flowered; solitary flowers few; central (terminal) flower present. Flowers 5-merous, salverform. Sepals triangular to lanceolate. Corolla tube bell-shaped, corolla lobes oblong-lanceolate. Filament tube short, filaments reduced, thecae base rounded, level with connective. Ovary oblong or long-ovoid, 1/3 flower length. Cypselae keeled, smooth, with lanceolate, persistent, pungent sepals.Receptacle lens-shaped, at fruit ripening, covered by persistent, accrescent, erect, lignified receptacle bracts (cephalioid), apical view and surrounded by cup-shaped receptacle after fruit dispersal.
Distribución:
Monotypic genus endemic to the Southern Cone of South America, in Argentina and Uruguay, growing from sea level to 3500 m altitude, in the Pampeana, Espinal, Chaqueña, Monte,
Patagónica, and Prepuneña biogeographic provinces.
