Nothoscordum is a genus of bulbous, herbaceous plants in the onion tribe (Allioideae) of the family Amaryllidaceae. The genus was formally described by Carl Sigismund Kunth in 1843 and comprises New World plants restricted in their native range to the Americas, from the southern United States south through Central America and across the length of South America, with particular diversity in Argentina, Uruguay, Brazil, Bolivia, Chile, and Peru.
The genus resembles its close relative Allium (onion and garlic) in its umbellate inflorescences and narrow, grass-like leaves arising from underground bulbs, but Nothoscordum species characteristically lack the pungent sulfurous odor associated with onions and garlic. Flowers are typically white to cream or pale pink with six tepals, borne on slender scapes. The genus is considered probably paraphyletic based on molecular studies.
Species counts vary significantly by authority: Plants of the World Online accepts 91 species, while some taxonomic treatments recognize only around 20. Several former members have been reclassified into related genera including Allium, Latace, Oziroe, and Tristagma. The most widespread species is N. gracile, which ranges from southern Mexico to Chile and has become naturalized in the southeastern United States, California, and scattered locations across Europe, Asia, Africa, and Australia.
Etymology
The name Nothoscordum was coined by Carl Sigismund Kunth in the fourth volume of his Enumeratio Plantarum (1843). It is a conserved name (nom. cons.) and is synonymous with Pseudoscordum, a name proposed by the botanist William Herbert in 1837 when he reclassified certain Allium species. The name alludes to the genus's resemblance to Scordum (garlic), with the Greek prefix notho- suggesting a spurious or false resemblance — reflecting the fact that these plants look like onions but lack their characteristic smell.
Distribution
Nothoscordum is native to the Americas, with its center of diversity in southern South America — particularly Argentina, Uruguay, Brazil, Bolivia, Chile, and Peru. The range extends northward through Central America into the southern United States, where N. bivalve occurs from California to Virginia. Several species, most notably N. gracile, have become naturalized far beyond the native range, establishing populations in southeastern North America, California, Europe, Asia, Africa, Australia, and various oceanic islands.
Taxonomy Notes
The genus belongs to subfamily Allioideae (the onion tribe) within Amaryllidaceae, the placement supported by current molecular phylogenetics and the Angiosperm Phylogeny Website. Molecular studies (Fay, Rudall & Chase 2006) suggest the genus is probably paraphyletic. Multiple GBIF backbone entries exist reflecting older classifications under Liliaceae and Alliaceae; the current consensus follows Amaryllidaceae. The genus is synonymous with Pseudoscordum Herb. (1837) and also encompasses the synonyms Beauverdia Herter (1943), Hesperocles Salisb. (1855), and Oligosma Salisb. (1866). Several species formerly placed here are now accepted in Allium, Latace, Oziroe, and Tristagma.
