Blossfeldia is a monotypic genus in the cactus family Cactaceae, comprising a single species, Blossfeldia liliputana. It holds the distinction of being the smallest known cactus in the world: mature plants reach only 10–12 mm in diameter, forming solitary stems or dense colonies of tiny dark-green bodies wedged into rock crevices. Unlike most cacti, Blossfeldia lacks ribs, tubercles, and spines entirely. Its seeds are hairy and bear an aril, and the plants have an unusually low stomata count with no thickened cuticle — a suite of traits unique within the family.
The genus is native to the central Andes of South America, occurring in northwestern Argentina (Jujuy, Salta, Tucumán, Catamarca, and Mendoza provinces) and southern Bolivia (Santa Cruz and Potosí departments). Plants grow at elevations of 1,200–3,500 m, almost always in the fissures of rocky cliffs, frequently near waterfalls where humidity is elevated.
Flowers are white, occasionally pink, 6–15 mm long, emerging from the stem apex. They are self-pollinating. The fruit is globose, red, and woolly. The genus was first described in 1937 by German botanist Erich Werdermann, based on material collected in northern Argentina in 1936 by Harry Blossfeld and Oreste Marsoner. Molecularly, Blossfeldia is phylogenetically isolated: it is sister to all other members of subfamily Cactoideae, prompting its placement in a dedicated tribe, Blossfeldieae, by Nyffeler and Eggli in their 2010 classification.
Etymology
The genus name Blossfeldia honors Harry Blossfeld, the German-Brazilian plant collector who discovered the species in northern Argentina in 1936. The sole species epithet, liliputana, alludes to Lilliput, the fictional land of miniature people in Jonathan Swift's Gulliver's Travels, reflecting the plant's remarkably tiny size.
Distribution
Blossfeldia is native to the central Andes, occurring in northwestern Argentina (Jujuy, Salta, Tucumán, Catamarca, and Mendoza provinces) and southern Bolivia (Santa Cruz and Potosí departments). Plants are restricted to elevations of 1,200–3,500 m, growing in rock crevices and cliff faces, frequently in the spray zone near waterfalls.
Ecology
Blossfeldia liliputana is a lithophyte adapted to extreme rock-crevice habitats in the high Andes. Its lack of a thickened cuticle and reduced stomata count suggest adaptation to consistently humid microsites, which explains its preference for cliff faces near waterfalls. The flowers are self-pollinating, reducing dependence on pollinators at high altitude.
Taxonomy Notes
The genus was described in 1937 by Erich Werdermann and has historically been difficult to place. It was at various times assigned to tribe Notocacteae and even to a separate subfamily, Blossfeldioideae. Molecular phylogenetic analyses consistently recover Blossfeldia as sister to the remaining members of subfamily Cactoideae, isolated from any other tribe. Nyffeler and Eggli (2010) formalised this by accepting tribe Blossfeldieae within Cactoideae. The sole species has also been published as Parodia liliputana (Werderm.) N.P.Taylor (1987), a nomenclatural synonym.
Cultivation
Blossfeldia liliputana is a niche collector's cactus valued for its extraordinary miniature size. It is typically grafted onto faster-growing cactus rootstock because the species grows very slowly and is susceptible to root rot on its own roots. Plants require extremely well-drained, mineral-lean substrate and should be kept dry in winter. High light and good airflow are essential; mist or high humidity near the growing point is tolerated but excess soil moisture is fatal.
