× Gasteraloe (also written × Gastrolea) is a nothogenus of succulent hybrid plants in the family Xanthorrhoeaceae, order Asparagales. Unlike a true genus, a nothogenus arises entirely from deliberate or spontaneous hybridization between distinct genera rather than from a common ancestor; the × prefix used in the name formally signals this status under the International Code of Nomenclature for algae, fungi, and plants.
The hybrids in × Gasteraloe result from crosses between species in the genus Gasteria and species in the genus Aloe or Aristaloe. Because of the two parent genera, the plants combine morphological traits from both: they are typically stemless or nearly stemless succulents whose fleshy leaves — usually spotted or marked with pale flecks and bearing small teeth along the margins — arrange themselves into compact rosettes. This rosette form and the distinctive leaf patterning make them popular ornamental plants.
Gonialoe variegata (formerly Aloe variegata) and Aristaloe aristata are among the parent species most frequently used in hybridization with gasterias, partly because they are notably more amenable to crossing with Gasteria than most other members of the aloe alliance. The nothogenus currently encompasses around 17 recognized hybrids and hybrid derivatives according to GBIF. Well-known cultivated forms include named hybrids such as 'Beguinii', 'King Richard', 'Dark Spike', and 'Marble Queen', reflecting the range of forms that decades of ornamental horticulture have produced.
Etymology
The name × Gasteraloe is a portmanteau of the two parent genera: Gasteria and Aloe. The × prefix, required by the International Code of Nomenclature for algae, fungi, and plants, denotes nothotaxon (hybrid) status and is not pronounced; the genus is spoken simply as "gasteraloe." An older synonym, × Gastrolea, combines the same parents in a different order.
Taxonomy Notes
× Gasteraloe is formally a nothogenus, a hybrid taxon recognized under the International Code of Nomenclature. It is not a naturally evolved genus but a category assembled from artificial and occasional spontaneous crosses between Gasteria and Aloe (or the segregate Aristaloe). GBIF places it within the family Xanthorrhoeaceae, order Asparagales. The nothospecies within it may be fertile or sterile — the nothogenus designation applies regardless of the viability of the hybrids' gametes. An alternative nothogenus name, × Gastrolea, exists for crosses where the Gasteria parent is treated as maternal; both names refer to the same pool of hybrids.
Cultivation
× Gasteraloe hybrids are widely cultivated as ornamental succulents. Their compact rosette habit and decorative spotted or marbled leaf patterning — inherited from both Gasteria and Aloe parents — suit them to pot culture indoors and to succulent gardens in frost-free climates. Gonialoe variegata and Aristaloe aristata are especially common as Aloe-side parents because of their strong compatibility with Gasteria in hybridization. The nothogenus encompasses numerous named cultivars — 'King Richard', 'Dark Spike', 'Black Giant', 'Marble Queen' among others — developed over many decades of succulent horticulture.
