Maihueniopsis

From M&J Cactus Wiki
Maihueniopsis
File:Maihueniopsis darwinii.jpg
Kingdom Plantae
Family Cactaceae
Subfamily Opuntioideae
Tribe Tephrocacteae
SubTribe
Genus Maihueniopsis
Species
Notes Taxonomy follows Joël Lodé (2015). Lodé treats Maihueniopsis as a distinct genus within the tribe Tephrocacteae.

Etymology

The name literally means "resembling Maihuenia," referring to its cushion-like growth habit which superficially looks like the genus Maihuenia, though they belong to different subfamilies.

Description

Maihueniopsis consists of low-growing, geophytic or cushion-forming cacti. They are highly specialized for high-altitude or cold-desert environments.

  • Stems: Segmented into small, globose, ovoid, or slightly flattened joints. The segments are often easily detached.
  • Spines: Variable; some species have strong, flattened, or needle-like spines, while others are nearly spineless. Glochids (tiny barbed bristles) are present but often deeply embedded in the areoles.
  • Leaves: Minute and ephemeral (falling off quickly), typical for the subfamily.
  • Flowers: Diurnal, appearing at the tips of the segments. They are relatively large and usually yellow, orange, or reddish.
  • Fruits: Globose to urceolate (urn-shaped), fleshy or dry, often containing a few large seeds.
  • Seeds: Large, covered with a pale, hard aril (typical for Opuntioideae), but with a specific shape characteristic of this genus.

Habitat

The genus is found in the high Andes (Puna) and the cold steppes of Patagonia. They grow in very well-drained, rocky or sandy soils, often at altitudes between 2000 m and 4500 m.

Distribution

  • South America: Argentina, Bolivia, Chile, and Peru.

Species and Subspecies

Following Lodé (2015), the genus includes 18 recognized species:

Taxonomy

The circumscription of Maihueniopsis has been subject to much debate. Lodé maintains it as a separate genus, including some species that others place in Puna or Cumulopuntia. He emphasizes the importance of seed morphology and the specific biogeography of the Tephrocacteae tribe.