Aponogeton robinsonii

Aponogeton robinsonii is rather rare in the aquarium hobby. It occurs in central and southern Vietnam as well as in Laos in slow-flowing rivers with very soft water, on muddy as well as on rocky substrate. Typical A. robinsonii is a plant that mainly develops floating leaves. There are also plants under that name that develop long, ribbon-shaped, wavy submerged leaves but no true floating leaves. They were first imported by Ingo Hertel in 1981 and commonly known as "normal" A. robinsonii. However these plants correspond with Aponogeton eberhardtii that was described as a separate species by A. Camus in 1912. A. eberhardtii is only known from Vietnam and was treated as a synonym of A. robinsonii for a long time. However, Josef Bogner (2018) and Helmut Mühlberg concluded that A. eberhardtii is distinguishable as a separate species.

Both, actual A. robinsonii as well as A. eberhardtii grow constantly under aquarium conditions, without a dormant stage, and flower frequently. The inflorescences have two spikes like many African and Madagascan but not Asian Aponogeton species. The white, fragrant flowers are arranged unilaterally along the spikes.

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