Blunt-leaved crucifixion thorn (Castela retusa)

Castela retusa - Endemic Spiny Shrub of Oaxaca, Mexico

Hailing from the dry tropical scrublands of southern Mexico, this rare spiny shrub is characterized by its distinct leaf shape. It is endemic to the state of Oaxaca, where it survives in dry, rocky terrains under intense sunlight.

Taxonomy

  • ∟ царство Plantae
  • ∟ division Tracheophytes (Vascular Plants)
  • ∟ subdivision Spermatophytes (Seed plants)
  • ∟ Angiosperms
  • ∟ mesangiosperms (Core angiosperms)
  • ∟ eudicots
  • ∟ Superrosids
  • ∟ rosids
  • ∟ malvids
  • ∟ order Sapindales
  • ∟ family Simaroubaceae (Quassia family)
  • ∟ genus Castela (Crucifixion Bush)
  • ∟ species Castela retusa (Blunt-leaved crucifixion thorn)

Living Pulse

Morphology

The plant grows as a rigid, thorny shrub with grayish branches. Its most distinguishing feature is the obovate leaves that possess a retuse apex, meaning the leaf tip has a shallow notch or indentation.

Its small, yellowish-green to reddish flowers are followed by small, single-seeded drupes. These morphological adaptations enable the plant to withstand prolonged dry seasons.

Applications

The plant contains bitter secondary metabolites typical of the Simaroubaceae family, which deter herbivores. While not widely cultivated, it has potential interest for chemical research into bioactive quassinoids.

Interesting facts

First collected and described by the Danish botanist Frederik Michael Liebmann in 1853, the species name retusa directly references its unique notched leaves. It remains a poorly studied species due to its restricted geographical range.

Geography of distribution

  • Mexico

Sources

  • Kew Royal Botanic Gardens (POWO)
  • World Flora Online (WFO)
  • Global Biodiversity Information Facility (GBIF)

Technical Information

External Databases: GBIF, POWO, Tropicos

See also