Anubias

''Anubias'' is a genus of aquatic and semi-aquatic flowering plants in the family Araceae, native to tropical central and western Africa. They primarily grow in rivers and streams, but can also be found in marshes. They are characterized by broad, thick, dark leaves that come in many different forms. The genus was revised in 1979 and since then its nomenclature has been stable. Species can be determined by using mostly characteristics of the inflorescence. Because of the often shady places where the plants grow, the genus was named after the Egyptian god Anubis, the god of the afterlife. The genus was first described in 1857 by Heinrich Wilhelm Schott, with '' A. afzelii'' as its type species.

Reproduction and uses

''Anubias'', most notably the varying forms of '' A. barteri'', are commonly used in aquariums, usually attached to rocks or bogwood. In contrast to most plants, ''Anubias'' generally prefer subdued lighting and can also produce flowers underwater. In the aquarium they should be placed in shaded areas, otherwise algae will develop on the leaves.

''Anubias'' are considered by many aquarists some of the easiest plants to maintain, since their light and nutrient requirements are very low and also because herbivorous fish will not eat it (with a few exceptions). This is why ''Anubias'' are some of the few plants which can be used in aquariums with African cichlids and goldfishes.

Reproduction in artificial environments can be accomplished by stolon division or from side shoots. The stolon must always be above the substrate in order to survive, otherwise it will rot and the plant dies. Rather than planting anubias directly into the soil, they should be attached to a piece of rock or driftwood, as they are more likely to grow and thrive when the rhizome and roots are left exposed instead of buried. It is also possible to propagate ''Anubias'' by seed.

The natural growth rate of all species in this genus is rather slow. Usually, they produce a leaf every 3 weeks, or even slower. And while they were once thought to be among the few plants that do not respond to CO₂ addition, .

The most commonly available species of this genus is ''Anubias barteri'' Schott, which is polymorphic and subdivided into several varieties. The largest members of the genus are ''Anubias gigantea'' Chevalier ex Hutchinson and ''Anubias heterophylla'' Engler. Their leaf-stems can grow up to 83 cm, with leaves 40 cm long and 14 cm broad with lateral lobes up to 28 cm long and 10 cm broad. The smallest representative is '' Anubias barteri var. nana'' (Engler) Crusio, with a height up to 10 cm and with leaves up to 6 cm long and 3 cm broad.

''Anubias'' can be grown emersed (above water). For this reason they may be used in paludariums.

Species and varieties

; ''Anubias afzelii'' Schott
* Narrow-leafed, medium-sized ''Anubias''
* Characteristics: plant with stolon
* Leaf-stem: up to 20 cm
* Leaves: 13–35 cm long, 3–13 cm broad
* Height in aquarium: 25 – 30 cm
Optimal conditions:
* Temperature: 22 - 28 °C
* pH: 6.0 - 7.0
* Water hardness: 2 dGH - 6 dGH
* Position in aquarium: middle to back
* Usual growth rate: one leaf every 2 months

; ''Anubias barteri'' Schott

Common varieties:

; ''Anubias barteri'' var. ''angustifolia'' (Engler) Crusio
* Synonym: ''Anubias lanceolata'' f. ''angustifolia'' Engler
* Narrow leaves, similar to ''afzelii'', but much smaller
* Leaf-stem: up to 32 cm
* Leaves: up to 18 cm long, up to 3.5 cm wide
* Height in aquarium: 10 – 15 cm
Optimal conditions:
* Temperature: 20 - 27 °C
* pH: 5.5 - 8.0
* Water hardness: < 8 dGH
* Position in aquarium: middle
* Usual growth rate: one leaf every 2 months

; ''Anubias barteri'' var. ''barteri''
* Compact, heart-shaped anubias
* Leaf-stem: up to 23 cm
* Leaves: 7–23 cm long, 4–11 cm wide
* Height in aquarium: 25 – 45 cm
Optimal conditions:
* Temperature: 20 - 27 °C
* pH: 5.5 - 9.0
* Water hardness: < 20 dGH
* Position in aquarium: back
* Usual growth rate: one leaf every 3 months

; ''Anubias barteri'' var. ''caladiifolia'' Engler
* Heart-shaped anubias
* Leaf-stem: up to 54 cm
* Leaves: 10–23 cm long, 5–14 cm wide
* Height in aquarium: 7 – 30 cm
Optimal conditions:
* Temperature: 20 - 27 °C
* pH: 5.5 - 8.0
* Water hardness: < 20 dGH
* Position in aquarium: middle to back
* Usual growth rate: one leaf every 2 months

; ''Anubias barteri'' var. ''glabra'' N. E. Brown
* Synonyms: ''Anubias lanceolata'' N. E. Brown, ''Anubias minima'' Chevalier.
* Narrow-leafed, large anubias
* Leaf-stem: up to 35 cm long
* Leaves: spear-shaped, up to 21 cm long, 9 cm wide
* Height in aquarium: 30 – 50 cm
Optimal conditions:
* Temperature: 22 - 27 °C
* pH: 5.5 - 8.0
* Water hardness: < 20 dGH
* Position in aquarium: back
* Usual growth rate: 4 - 8 leaves per year

; ''Anubias barteri'' var. ''nana'' (Engler) Crusio
* Synonym: ''Anubias nana'' Engler
* Dwarf, creeping, with heart-shaped leaves
* Leaf-stem: up to 5 cm long
* Leaves: up to 6 cm long and 3 cm wide
* Height in aquarium: 5 – 10 cm
Optimal conditions:
* Temperature: 22 - 27 °C
* pH: 5.5 - 9.0
* Water hardness: 3 - 10 dGH
* Position in aquarium: front
* Usual growth rate: one leaf every month

; ''Anubias gigantea'' Chevalier ex Hutchinson
* Synonyms: ''Anubias gigantea'' var. ''tripartita'' Chevalier, ''Anubias hastifolia'' var. ''robusta'' Engler
* Large arrow-shaped leaves
* Leaf-stem: up to 83 cm long
* Leaves: up to 30 cm long and 14 cm wide, with large lateral lobes up to 28 cm long and 10 cm broad
* Seldom used in aquariums

; ''Anubias gilletii'' De Wildeman & Durand
* Initially heart-shaped, later with long rear fringes
* Leaf-stem: up to 40 cm
* Leaves: arrow-shaped, 25 cm long, 12 – 13 cm wide, lateral lobes up to 13 cm long
* Height in aquarium: 25 – 40 cm
Optimal conditions:
* Temperature: 22 - 27 °C
* pH: 6.0 - 8.0
* Water hardness: 4 - 10 dGH
* Position in aquarium: back
* Usual growth rate: 2 - 6 leaves per year

; ''Anubias gracilis'' Chevalier ex Hutchinson
* Whether this is a separate species or another variety of ''Anubias barteri'' is doubtful
* Leaf-stem: up to 33 cm
* Leaves: triangular heart-shaped, 12 cm long, 4–10 cm wide, lateral lobes up to 7 cm long and 3 cm wide
* Height in aquarium: 20 – 30 cm
Optimal conditions:
* Temperature: 24 - 27 °C
* pH: 6.0 - 8.0
* Water hardness: 5 - 12 dGH
* Position in aquarium: middle to back
* Usual growth rate: 2 - 6 leaves per year

; ''Anubias hastifolia'' Engler
* Synonyms: ''Amauriella hastifolia'' (Engler) Hepper, ''Anubias hastifolia'' var. ''sublobata'' Engler, ''Anubias auriculata'' Engler, ''Amauriella auriculata'' (Engler) Hepper, ''Anubias haullevilleana'' De Wildeman, ''Anubias laurentii'' De Wildeman, ''Amauriella obanensis'' Rendle, ''Amauriella talbotii'' Rendle
* Leaves: long heart-shaped
* Leaf-stem: up to 67 cm long
* Leaves: up to 33 cm long and 14 cm wide, lateral lobes up to 26 cm long and 8 cm broad
* Height in aquarium: 30 – 50 cm
Optimal conditions:
* Temperature: 22 - 27 °C
* pH: 6.0 - 8.0
* Water hardness: < 20 dGH
* Position in aquarium: middle to back
* Usual growth rate: 2 - 6 leaves per year

; ''Anubias heterophylla'' Engler
* Synonyms: ''Anubias congensis'' N. E. Brown, ''Anubias congensis'' var. ''crassispadix'' Engler, ''Anubias affinis'' De Wildeman, ''Anubias engleri'' De Wildeman, ''Anubias bequaerti'' De Wildeman, ''Anubias undulata'' (trade name)
* Very large species, for tall aquariums
* Leaf-stem: up to 66 cm long
* Leaves: 38 cm long, 13 cm wide, sometimes with very short basal lobes
* Height in aquarium: 25 – 60 cm
Optimal conditions:
* Temperature: 24 - 27 °C
* pH: 5.5 - 8.0
* Water hardness: 5 - 12 dGH
* Position in aquarium: back
* Usual growth rate: 2 - 4 leaves per year

;'' Anubias pynaertii'' De Wildeman
* Leaf-stem: up to 45 cm
* Leaves: up to 29 cm long and 14 cm broad

See also

* Aquatic plant
*List of freshwater aquarium plant species

References

{{Taxonbar, from=Q112429

Araceae genera
Flora of West Tropical Africa
Flora of West-Central Tropical Africa
Flora of Angola
Aquarium plants