Beschorneria dubia Carrière is the most enigmatic species in the genus Beschorneria. Its original description by Elie Abel Carrière — the 19th-century chief gardener of the Paris Natural History Museum — was noted as “somewhat ambiguous” by later taxonomists, and the species has remained poorly understood ever since. POWO accepts the name and places it in Tamaulipas (central Mexico), but detailed morphological data, ecological information and cultivation records are virtually non-existent in the accessible literature.
Taxonomy and nomenclature
Described by Elie Abel Carrière (1818–1896), a French horticulturist and botanist. Family Asparagaceae, subfamily Agavoideae. The epithet dubia (Latin: “doubtful” or “uncertain”) almost certainly reflects the original author’s own uncertainty about the taxonomic placement or identity of the plant — an unusually candid admission that has not helped the species’ subsequent reputation. POWO accepts the name with native range listed as Tamaulipas.
Distribution and natural habitat
POWO gives the native range as Tamaulipas, north-eastern Mexico. The Tamaulipas location places this species in the same broad geographic area as Beschorneria septentrionalis — the northernmost and hardiest beschorneria. However, without precise locality or altitude data, no firm conclusions can be drawn about its ecology or cold tolerance.
Cultivation guide
| Hardiness | −4 to −6 °C / 21–25 °F (estimated; USDA zones 9a–9b) |
| Documentation level | ★ — virtually no cultivation data available |
| Availability | Not in the commercial trade |
No cultivation records could be found. The Tamaulipas origin suggests moderate to good cold tolerance, potentially comparable to Beschorneria septentrionalis if the species shares a similar altitude range — but this remains purely speculative. Beschorneria dubia is not available in the horticultural trade and would only be encountered through botanical garden exchanges or targeted field collection.
References
POWO (2026). Beschorneria dubia Carrière. Plants of the World Online, Kew.