Chiliotrichum is a genus of flowering plants in the daisy family (Asteraceae, order Asterales), native to southern South America. It comprises evergreen shrubs that are branched and densely leafy, with alternate, entire, sessile leaves. The flower heads (capitula) are daisy-like — heterogamous and radiate — borne singly at the ends of long peduncles. Each head has white, pistillate ray florets surrounding a central disc of numerous yellow, perfect, tubular florets. The involucre is campanulate with 2–4 series of graduated phyllaries, and the receptacle bears linear-ovate, scarious paleae. The fruits are cylindrical, ribbed achenes with glandular hairs, topped by a pappus of several series of scabrous bristles of varying lengths — a feature reflected in the genus name Chiliotrichum, from Greek roots meaning "thousand hairs." The genus was described by Cassini in 1817. Of the 15 species historically described, four are currently accepted: C. angustifolium, C. diffusum, C. rosmarinifolium, and C. tenue. C. diffusum is the most widespread, occurring in Chile, Argentina, and the Falkland Islands, while the others are more restricted to Chile and Argentina.
Etymology
The genus name Chiliotrichum derives from the Greek χίλιοι (chilioi, "thousand") and θρίξ (thrix, "hair"), referencing the pappus — a structure of numerous scabrous bristles in several series of varying lengths that crowns each achene.
Distribution
Chiliotrichum is endemic to southern South America. Its four accepted species are distributed across Chile, Argentina, and the Falkland Islands (Islas Malvinas). C. diffusum has the broadest range, found in all three regions, while C. angustifolium and C. tenue are restricted to Chile, and C. rosmarinifolium occurs in both Chile and Argentina.
Taxonomy
The genus Chiliotrichum was described by the French botanist Alexandre Henri Gabriel de Cassini and published in the Bulletin des Sciences, par la Société Philomathique de Paris in 1817. It belongs to the family Asteraceae within the order Asterales. Of the 15 species historically described under the genus, only four are currently accepted. GBIF records only 2 descendant species, suggesting some taxonomic disagreement regarding the circumscription of the genus.
