Echinopsis

Taxonomy

Studies in the 1970s and 1980s resulted in several formerly separate genera being absorbed into Echinopsis. When very broadly circumscribed, Echinopsis sensu lato included over 100 species. Some genera have been absorbed and then accepted again. For example, the genus name Trichocereus was given to a number of columnar cacti in 1909 by Vincenzo Riccobono. The genus was subsumed into Echinopsis in 1974 by Friedrich, along with Lobivia. In 2011, it was argued that Trichocereus was distinct from Echinopsis, and a 2012 genetic and morphological study by Albesiano found Trichocereus to be monophyletic if it included three species of Harrisia.

A 2012 genetic analysis of chloroplast DNA indicated Echinopsis was made up of several divergent lineages. This was shown again in 2019. It was concluded that previous taxonomic confusion was due to convergent evolution: species in different lineages had evolved to have similar growth and/or to share pollinators.

, Plants of the World Online subsumed Soehrensia, Chamaecereus, Trichocereus, and Lobivia into Echinopsis, resulting in a genus of around 80 species.

Species

Species of Echinopsis accepted by Plants of the World Online :

In addition, many hybrids exist, mostly between similar species, such as the cross between Echinopsis pachanoi (formerly Trichocereus macrogonus var. pachanoi) and E. eyriesii (now E. oxygona) which was sold under the name "Trichopsis pachaniesii" by Sacred Succulents.

Distribution

Echinopsis species are native to South America (Argentina, Bolivia, Peru, Brazil, Paraguay and Uruguay).

Cultivation

The growing and resting seasons for Echinopsis are the same as for Echinocactus. Research by J. Smith (former Curator at the Royal Botanic Gardens, Kew) showed that species like the Chilean Echinopsis cristata and its Mexican relatives thrive if potted in light loam, with a little leaf mould and a few nodules of limestone. The limestone keeps the soil open; it is important that the soil should be well drained.

Gallery

Image:Echinopsis eyriesii.JPG|Echinopsis oxygona visited by a European honeybee; Kfar Blum Kibbutz garden, Israel. Image:Echinopsis oxygona13213404.jpg|Echinopsis oxygona

References

Bibliography

• Edward F. Anderson, The Cactus Family (Timber Press, 2001) , pp. 255–286
• K. Trout, Trout's Notes on San Pedro & related Trichocereus species (Sacred Cacti 3rd ed. Part B) (Moksha Press, 2005)

References

1. (2019). "Phylogenetic Relationships and Evolutionary Trends in the Cactus Family". Journal of Heredity.
2. Schick, Robert. (2011). "''Echinopsis'' sensu stricto and ''Trichocereus'': Differentiating the Genera". Cactus and Succulent Journal.
3. (2012). "Cladistic Analysis of ''Trichocereus'' (Cactaceae: Cactoideae: Trichocereeae) Based on Morphological Data and Chloroplast Dna Sequences: Dedicated to Omar Emilio Ferrari (1936-2010)". Haseltonia.
4. (2012). "Molecular phylogenetics of ''Echinopsis'' (Cactaceae): Polyphyly at all levels and convergent evolution of pollination modes and growth forms". American Journal of Botany.
5. "''Echinopsis'' Zucc.".
6. "Sea-urchin cactus {{!}} Description, Distribution, & Facts {{!}} Britannica".