Codonanthopsis is a genus of flowering plants in the family Gesneriaceae (order Lamiales), placed in subfamily Gesnerioideae, tribe Gesnerieae, subtribe Columneinae, where it forms a clade with the related genera Nematanthus, Codonanthe and Lesia. It comprises trailing or hanging epiphytic subshrubs, native from southern Mexico through Central America and Trinidad and Tobago to Bolivia and most of Brazil.
Plants typically have stems 0.3–1 m long (occasionally to 2 m) that root adventitiously along their length, with fleshy, variably shaped leaves often bearing reddish nectaries on the underside. The funnel-shaped flowers are white, yellowish or pinkish, produced singly or in small clusters in the upper leaf axils, with five fused petals, a short spur, and four stamens with paired anthers joined by a narrow connective. Fruits are berrylike capsules with small seeds.
Most Codonanthopsis species grow within ant gardens and have a mutualistic relationship with arboreal ants: the plant provides nectar and fruit pulp as food and offers its roots as structural support for the ants' nests, while the ants in turn disperse the seeds, which germinate more readily once the ants remove the fleshy arils. This distinguishes Codonanthopsis from its close relative Codonanthe, whose species do not grow in ant gardens.
The genus was described in 1934 by Rudolf Mansfeld with just two species. It remained small for decades until molecular phylogenetic studies in the early 2010s revealed that Codonanthe was not a natural (monophyletic) group, with several of its species more closely related to Codonanthopsis. In 2013 ten species were accordingly transferred from Codonanthe to Codonanthopsis, substantially expanding the genus to its current size.
Some species, such as Codonanthopsis elegans, are grown as ornamental houseplants — typically in hanging baskets with a well-drained, soilless mix and humidity above 50% — though they remain less widely cultivated than Codonanthe.
Distribution
Native from southern Mexico through Central America and Trinidad and Tobago to Bolivia and most of Brazil (all but the southernmost region).
Ecology
Most species live in ant gardens, forming a mutualism with arboreal ants (notably Azteca in Brazilian Amazonia): the plant supplies nectar and fruit/aril food and root support for ant nests, while the ants disperse and help germinate the seeds by removing the arils.
Cultivation
A few species, especially Codonanthopsis elegans, are grown as ornamental houseplants in hanging baskets, preferring a well-drained soilless mix and humidity above 50%; the genus is generally more heat-tolerant but less widely cultivated than its relative Codonanthe.
Taxonomy Notes
Described in 1934 by Rudolf Mansfeld with two species; remained small until 2013, when molecular phylogenetics showed Codonanthe was not monophyletic and ten species were transferred into Codonanthopsis, considerably expanding the genus. GBIF corroborates the 1934 Mansfeld authorship and placement in Gesneriaceae/Lamiales; Wikipedia further places it in subfamily Gesnerioideae, tribe Gesnerieae, subtribe Columneinae, alongside Nematanthus, Codonanthe and Lesia.
