Corrigiola, commonly known as strapworts, is a genus of flowering plants in the family Caryophyllaceae, placed in the order Caryophyllales. Together with the closely related genus Telephium, it forms the small tribe Corrigioleae. The genus comprises a small number of species — around five are currently accepted — and is notable for its highly disjunct global distribution, occurring in Mexico, South America, southern and eastern Africa, Madagascar, northwestern Africa, Europe, and western Asia.
Plants in the genus are typically low-growing, with prostrate or spreading stems that branch mainly in the inflorescence. The leaves are narrow-lanceolate, blue-green, and glabrous, with small white-membranous stipules at the base. Flowers are small, 5-merous, borne in terminal clusters, with white petals slightly shorter than the brownish-green sepals. The fruit is a single-seeded nutlet a little over 1 mm in length.
The best-known species, Corrigiola litoralis (strapwort), is native to western Europe and the Mediterranean region and typically grows on moist, acidic, sandy or gravelly soils along riverbanks, lake shores, cultivated fields, and roadsides. It has declined significantly in parts of its range; in Switzerland it is listed as Critically Endangered (Possibly Extinct). Corrigiola telephiifolia, native to the western Mediterranean, is a somewhat more robust perennial relative.
Distribution
Corrigiola has a highly disjunct global distribution, with species native to Europe, western Asia, northwestern Africa, Madagascar, southern and eastern Africa, Mexico, and South America. In Europe the genus reaches its northern limits in the Atlantic and Mediterranean zones; the type species C. litoralis grows primarily on moist, acidic, sandy-gravelly soils along river shores and lake margins at lower elevations.
Ecology
Species of Corrigiola favour open, disturbed habitats on moist, acidic, sandy or gravelly substrates — riverbanks, lakeshores, arable fields, and roadsides. The prostrate habit and small, clustered flowers are adapted to the low, sparse vegetation of such seasonally disturbed shores.
Conservation
Corrigiola litoralis is assessed as Critically Endangered (Possibly Extinct) (CR(PE)) on the Swiss National Red List (2016) and is designated as a high national conservation priority (Priority 2) in Switzerland. Habitat loss through river engineering, bank stabilisation, and agricultural intensification are among the principal threats to this species across its European range.
Taxonomy Notes
Corrigiola belongs to the tribe Corrigioleae within Caryophyllaceae, a grouping it shares solely with Telephium. GBIF recognises five accepted species in the genus. The name Corrigiola litoralis and the alternative spelling C. littoralis appear in the literature; both forms refer to the same taxon, reflecting a historical orthographic variation.
