Anubias

Anubias

The African genus Anubias belongs to the Araceae family and is popular worldwide in the aquarium and paludarium hobby. With its robust leaves, slow growth, and remarkable ability to survive under a variety of conditions, Anubias is a stable base plant in both beginner and expert setups. The plants are distinguished by their thick, creeping rhizome and the striking inflorescence typical of the Araceae: a compact spadix surrounded by a bract (spathe).

Taxonomy and species

The genus was first described by Heinrich Wilhelm Schott in 1857 and was extensively revised taxonomically by Willem E. Crusio in 1979, who is still considered the standard reference for Anubias. The genus comprises approximately 9 recognized species and several subspecies, of which various natural variations and cultivars have entered the trade. The species are:

• Anubias afzelii
• Anubias barteri (with varieties such as var. nana, var. coffeefolia, and var. glabra)
• Anubias gigantea
• Anubias gilletii
• Anubias gracilis
• Anubias hastifolia
• Anubias heterophylla
• Anubias pynaertii

These species are native to tropical West and Central Africa, from Nigeria to Congo and Gabon, where they mainly occur along rivers, streams, and swamps.

Ecology and natural habitat

Anubias is a distinct rheophyte: a plant that specializes in growing on rocks, wood, or banks in flowing water. The rhizome attaches itself firmly to hard material, while the leaves are resistant to currents and periodic flooding. Many species grow half-submerged in shady forest areas and can easily switch between emersed and submerged conditions. This explains their exceptional adaptability in aquariums.

In nature, Anubias plants are often important hiding places for fish, shrimp, and other aquatic organisms. They provide shelter from predators and serve as a substrate for biofilm and algae on which microfauna live.

Keeping in the aquarium

Anubias is one of the most maintenance-friendly aquarium plants. Important guidelines:

• Rhizome above substrate: The rhizome should never be buried in the soil, as this will cause it to rot. Secure the plant to wood or stone with wire or glue.
• Light requirements: Low to moderate light intensity is sufficient. Under bright light, the plant grows faster, but the chance of algae growth on the leaves also increases.
• Nutrition and CO₂: Although Anubias has few requirements, the plant benefits from a balanced supply of nutrients and optional CO₂. Absorption mainly takes place via the leaf surface.
• Growth and propagation: The plant grows slowly. Propagation is achieved by cutting the rhizome, with each section bearing at least a few leaves.
• Compatibility: Due to their sturdy leaves, Anubias species are ideal for aquariums with herbivorous fish (such as cichlids), which often damage softer plants.

Use in aquascaping and ponds

Thanks to their robust appearance and dark green leaves, Anubias plants are popular as contrasting plants in aquascapes. They are often used to accentuate wood and stones in layouts, and provide a natural look in biotope aquariums that mimic African rivers. Some species, such as A. gigantea and A. hastifolia, are also suitable as shore and paludarium plants in pond and terrarium setups.

Flowering in culture

Under aquarium conditions, Anubias sometimes flowers spontaneously. The flowers appear on a short stem above the rhizome. Although flowering has no aesthetic added value compared to the graceful leaves, it is an interesting biological feature that emphasizes the close relationship with other arum lilies.

Conservation and trade

The genus is widely available in the trade, largely originating from commercial nurseries that propagate Anubias via rhizome division or micropropagation. These cultivation methods are sustainable and reduce pressure on wild populations. Nevertheless, in some regions, they are still harvested from the wild, especially rarer species and varieties. Sustainable cultivation is therefore preferable.

Conclusion

Anubias combines scientific value with great popularity among aquarium and paludarium keepers. The genus is a textbook example of how ecological adaptations—rheophytic life, tolerance for emersed and submerged conditions—have led to a robust and versatile plant that is perfectly suited for use in the hobby.