Hatiora

From M&J Cactus Wiki
Hatiora
File:Hatiora salicornioides.jpg
Kingdom Plantae
Family Cactaceae
Subfamily Cactoideae
Tribe Rhipsalideae
SubTribe
Genus Hatiora
Species
Notes Taxonomy follows Joël Lodé (2015). Lodé treats Hatiora in a restricted sense, excluding Rhipsalidopsis.

Etymology

The name is an anagram of the surname of Thomas Hariot (1560–1621), a British mathematician and cartographer who was a protégé of Sir Walter Raleigh.

Description

Hatiora consists of small, epiphytic or lithophytic cacti that grow as much-branched shrubs.

  • Stems: Composed of short, cylindrical, or club-shaped (clavate) segments. The branching is typically dichotomous or in whorls.
  • Areoles: Located at the tips of the segments, where new joints and flowers emerge.
  • Flowers: Diurnal and relatively small. They are funnel-shaped and appear at the terminal areoles. Colors range from yellow to orange.
  • Fruits: Small, globose to turbinate berries, which are translucent or whitish when ripe.
  • Seeds: Small, dark brown or black, and smooth.

Habitat

The genus grows in the Atlantic rainforests (Mata Atlântica) of Brazil. These cacti are epiphytes, growing on the mossy branches of trees, or lithophytes, growing on shaded rock faces, from sea level up to 1800 m.

Distribution

  • Brazil: Endemic to the southeastern and southern regions (Bahia, Espírito Santo, Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina).

Species and Subspecies

Following the restricted classification of Lodé (2015), the genus includes 3 recognized species and 1 subspecies:

Taxonomy

The taxonomy of Hatiora has been controversial. Lodé maintains the genus only for the species with cylindrical segments (Subgenus Hatiora). He treats the flat-segmented species (the "Easter Cacti") as the distinct genus Rhipsalidopsis, supported by both morphological differences (floral symmetry) and molecular studies (Korotkova, 2011).