Guilleminea densa var. densa has been reported from several U. S. states (e.g., J. T. Kartesz and C. A. Meacham 1999). J. Henrickson (1987) implicitly rejected those records, stating that the variety 'as considered here is widespread in South America, naturalized in southern Africa, and Queensland, Australia, but does not occur in North America.'

Wiggins 1964, FNA 2004

Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Prostrate, mat-forming perennial herb from a woody root; stems densely lanate, much branched, 3-30 cm long. Leaves: Basal leaves early-deciduous, petiolate; cauline leaves opposite, short-petiolate, blades elliptic to oval, asymmetric, abruptly narrowed at base, acute or rounded at apex, 2-10 mm wide, 3-15 mm long, glabrous above and woolly pubescent underneath. Flowers: White to cream, in dense glomerules, these sessile in the leaf axils; each flower in glomerule subtended by ovate-acute, white, scarious bracts, 1 mm long; calyx white-scarious, 2 mm long, lobes lance-ovate, actue, glabrous. Fruits: Utricle glabrous, compressed-ovate, about equaling perianth tube, seeds ovoid-lentiular, 0.5 mm long, brown, lustrous. Ecology: Found on dry soil in mostly disturbed areas, from 2,500-6,000 ft (762-1829 m); flowers May-October. Distribution: s CA, AZ, NM, TX, CO, OK; south through MEX to S. America; naturalized in Australia, S. Africa. Notes: Distinguished by its prostrate, mat-forming habit; mostly hairless, shiny, dark green upper sides of leaves with long, soft hairs below; axillary inflorescences of densely clustered whitish bracts and tiny flowers. There are 5 species in the genus but G. densa is the only one found in North America. Our material belongs to G. densa var. aggregata. Ethnobotany: Unkown Etymology: Guilleminea is named for Jean Baptiste Antoine Guillemin (1796-1842) a French botanist and author; densa means compact or dense. Synonyms: Brayulinea densa, Illecebrum densum Editor: SBuckley 2010, FSCoburn 2014, AHazelton 2015