Aiphanes - Taxonomy

Taxonomy

Aiphanes is placed in the subfamily Arecoideae, the tribe Cocoseae and the subtribe Bactridinae, together with the genera Desmoncus, Bactris, Acrocomia and Astrocaryum.

In his 1932 revision of the genus, German botanist Max Burret recognised 32 species. Seventeen of these were new species, mostly based on collections made by German botanist Wilhelm Kalbreyer in northern Colombia between 1877 and 1881. Working with a very narrow species concept, and not being familiar with the variation present in natural populations, Burret placed almost every specimen into a distinct species. The bombing of the Berlin Herbarium during the Second World War destroyed the only known collections for 13 of these 32 species, further complicating the situation.

The International Code of Botanical Nomenclature requires each species to be represented by a type collection. The destruction of Burret's type collections left many species only known from his original descriptions, which generally lacked illustrations. Other specimens (called neotypes) were designated to replace these, either by Rodrigo Bernal and colleagues in 1989 or by Borchsenius and Bernal in their 1996 monograph of the genus. Bernal and colleagues attempted to retrace Kalbreyer's travels in northern Colombia and collect specimens from as close as possible to the location of the original collections.

Burret divided Aiphanes into two subgenera, Brachyanthera and Macroanthera. Eleven species were placed in Macroanthera, while the remainder were placed in Brachyanthera. In their 1996 monograph, Borchsenius and Bernal questioned the applicability of these subgenera. They recognised that if Macroanthera was reduced to three species (A. horrida, A. eggersii and A. minima) it could form a viable grouping, but that this would leave Brachyanthera overly heterogeneous. Consequently, they abandoned Burret's use of subgenera.

In the three decades following Burret's delimitation of the genus a further 15 species were described, bringing the total species count to 47. Borchsenius and Bernal determined that many of these names were synonyms, although American botanist George Proctor disagreed with their decision to lump A. acanthophylla into A. minima. Borchsenius and Bernal also described one new species, Aiphanes spicata, bringing the total number of accepted species to 22. In two cases the destruction of the only known collections made it impossible to be absolutely certain that a name was a synonym. The current World Checklist of Selected Plant Families, maintained by Rafaël Govaerts at the Royal Botanic Gardens, Kew, recognises 26 species, including four species described since the publication of Borchsenius and Bernal's monograph.

Burret divided Aiphanes into two subgenera, Brachyanthera and Macroanthera. Eleven species were placed in Macroanthera, with the remainder in Brachyanthera. In their 1996 monograph, Borchsenius and Bernal questioned the applicability of these subgenera. They recognised that if Macroanthera was reduced to three species (A. horrida, A. eggersii and A. minima) it could form a viable grouping, but that this would leave Brachyanthera overly heterogeneous. Consequently, they abandoned Burret's use of subgenera.