Ambrosina is a monotypic genus of flowering plants in the family Araceae (order Alismatales), constituting the sole genus of the tribe Ambrosineae. It contains a single living species, Ambrosina bassii, which holds the distinction of being the smallest terrestrial aroid in the Mediterranean region, rarely exceeding 8 cm in height.
The plant produces oval leaves measuring 3.5 to 6 cm in length that closely resemble the foliage of aroid seedlings, giving mature plants a deceptively juvenile appearance. Its inflorescence is compact, approximately 2.5 cm long and bent over, enclosed within a distinctive spathe that is egg-shaped, greenish-brown, and dotted. Unusually, the interior of this spathe is divided into two separate chambers: one contains a solitary female flower, while the other houses 8 to 10 male flowers. Seeds bear an elaiosome, but sexual reproduction is infrequent, as the species exhibits a notably low reproductive rate.
Ambrosina bassii is native to the western Mediterranean basin, occurring in Sardinia, Corsica, Sicily, southern mainland Italy, Tunisia, and Algeria. It favours north-facing woodland slopes where humus-rich soil accumulates over limestone bedrock.
The genus name commemorates the Italian brothers Bartolomeo Ambrosini (1588–1657) and Giacinto Ambrosini (1605–1671), both notable naturalists. Several species formerly placed in Ambrosina — including A. ciliaris, A. ciliata, A. retrospiralis, and A. spirialis — have since been transferred to the genus Cryptocoryne.
Etymology
The generic name Ambrosina honours the Italian brothers Bartolomeo Ambrosini (1588–1657) and Giacinto Ambrosini (1605–1671), both prominent naturalists of their era.
Distribution
Ambrosina bassii is distributed across the western Mediterranean, occurring in Sardinia, Corsica, Sicily, southern mainland Italy, Tunisia, and Algeria. It typically grows in woodland habitats on north-facing hillsides, in humus-rich soils overlying limestone.
Ecology
Ambrosina bassii foliage can be affected by the phytopathogenic fungus Entylomaster dietelianus (syn. Entyloma dietelianum), which causes reddish-brown leaf spots up to 1 mm in size containing numerous 10–16 μm spores. This fungal disease is specific to the family Araceae.
Conservation
Ambrosina bassii is assessed as Least Concern on the IUCN Red List of Threatened Species. Despite this global assessment, the species is legally protected in France.
Taxonomy Notes
Ambrosina is the sole genus of the tribe Ambrosineae within the family Araceae. The genus is strictly monotypic, with Ambrosina bassii as its only accepted species. Several former members — Ambrosina ciliaris, A. ciliata, A. retrospiralis, A. roxburghiana, A. spirialis, and A. unilocularis — have been reassigned to Cryptocoryne.
