Isolatocereus

From M&J Cactus Wiki
Isolatocereus
File:Isolatocereus dumortieri.jpg
Kingdom Plantae
Family Cactaceae
Subfamily Cactoideae
Tribe Phyllocacteae
SubTribe Echinocereinae
Genus Isolatocereus
Species
Notes Taxonomy follows Joël Lodé (2015). Lodé treats it as a distinct monotypic genus, separate from Stenocereus.

Etymology

The name is derived from the Latin isolatus (isolated) and cereus (candle), referring to the isolated position of the genus in early classifications or its imposing, solitary appearance.

Description

Isolatocereus is a monotypic genus containing the species I. dumortieri. It is a massive, tree-like cactus that can reach heights of up to 15 meters.

  • Stems: Erect, branching from a short woody trunk. The branches are glaucous green, often appearing somewhat constricted at intervals (segmentation).
  • Ribs: Typically 5 to 8, high and well-defined.
  • Spines: Short, greyish, and needle-like, emerging from closely set areoles.
  • Flowers: Diurnal or crepuscular, relatively small for the size of the plant, funnel-shaped. They are greenish-white or pale pinkish and appear along the ribs near the apex.
  • Fruits: Small, globose to ovoid, and fleshy. They are reddish and dehisce (open) irregularly when ripe.
  • Seeds: Small, black, and shiny.

Habitat

The genus grows in tropical deciduous forests and xerophytic scrubs on rocky slopes and canyons. It is a dominant feature of the landscape in its native range. Altitudinal range: 300–2000 m.

Distribution

  • Mexico: Central regions (Aguascalientes, Guerrero, Hidalgo, Jalisco, Michoacán, Morelos, Oaxaca, Puebla, Querétaro, San Luis Potosí, Veracruz).

Species

Following the classification of Lodé (2015), the genus includes only one species:

Taxonomy

Often included in Stenocereus (as S. dumortieri), Lodé maintains Isolatocereus as a separate genus based on its distinct floral development and the unique structure of its pollen. Molecular evidence suggests it occupies a somewhat intermediate position between the larger columnar clades.