Setiechinopsis
From M&J Cactus Wiki
| Setiechinopsis | |
|---|---|
| File:Setiechinopsis mirabilis.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Cereeae |
| SubTribe | Trichocereinae |
| Genus | Setiechinopsis |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015) with molecular insights from Ritz et al. (2007), Las Peñas et al. (2010), Albesiano & Kiesling (2012), and Schlumpberger & Renner (2012). |
Etymology
The name means "Echinopsis with bristles", referring to the floral tube covered with characteristic hairs and bristles.
Description
Setiechinopsis is a monotypic genus of small, short-lived cacti with a distinctive floral morphology.
- Habit: Small, usually solitary; sometimes branching; lifespan typically 3–5 years.
- Roots: Short, thick taproot with fine secondary roots.
- Stems: Cylindrical, strongly pigmented; brownish or purplish-green to nearly black.
- Ribs: 11–12, low and straight.
- Areoles: Covered with white wool.
- Spines: 9–14 radial spines; 1 longer central spine; fine and slightly pubescent.
- Flowers: Nocturnal, funnel-shaped, white, strongly scented; appearing near the apex; self-fertile.
- Floral tube: Very long, slender, scaly, covered with hairs and bristles.
- Pollination: By long-tongued moths (e.g. Manduca sexta).
- Fruits: Fusiform, drying at maturity; longitudinally dehiscent; floral remains persistent.
- Seeds: Globose to elongated, dark brown, dull, tuberculate, with mucilage.
Habitat
Occurs in unusual habitats for cacti:
- saline and brackish soils
- grasslands and open shrublands (e.g. Atriplex)
- foothills and low mountain areas
Altitude range: approximately 200–1250 m.
Distribution
Argentina:
- Catamarca
- La Rioja
- Mendoza
- San Juan
- San Luis
- Santiago del Estero
Taxonomy
The genus has a complex history but is now widely accepted.
Key points:
- Originally described as Echinopsis mirabilis (Spegazzini, 1905)
- Later transferred to multiple genera (Arthrocereus, Acanthopetalus)
- Often included in Echinopsis sensu lato in modern classifications
- Ritz et al. (2007): showed it is not part of Echinopsis
- Las Peñas et al. (2010): cytogenetic evidence supports separation
- Albesiano & Kiesling (2012): identified multiple autapomorphies
- Schlumpberger & Renner (2012): placed it basally in a clade with Denmoza and related taxa
The genus is therefore recognized as distinct and evolutionarily isolated.
Species
Monotypic genus:
Notes
- One of the shortest-lived genera within Cactaceae.
- Morphology shows strong convergence with Echinopsis, but molecular data contradicts this relationship.
- Adapted to atypical, often saline environments.
- Represents an early-diverging lineage within its clade.
