Blyxa aubertii

Author: Bryce Millar, MD

Common Names: Roundfruit Blyxa

Division: Magnoliophyta

Class: Liliopsida

Order: Alismatales

Family: Hydrocharitaceae

Native Distribution: Southeast Asia, Madagascar, Japan, Australia, reported also in Southern Louisiana

Aquarium Placement: Midground in larger tanks, background in medium-sized tanks

Requirements: Moderate to bright illumination, CO2 addition recommended

Plant Description

Blyxa aubertii is a species that has been around for many years, but it is not terribly popular and has never become truly well-established in the hobby. The reason for this is not entirely clear. This plant is perhaps slightly more demanding than its more common relative, B. japonica, but it has much to offer in terms of size and appearance.

Unlike many aquarium plants, B. aubertii is a true aquatic, found in a variety of submerged environments. These plants are part of the Hydrocharitaceae tape-grass family, and this is quite descriptive of the appearance of individual leaves. The plant appears to be a classic rosette, but closer inspection reveals an internal structure of short stems.

A routine program of fertilization with attention to macro and micro nutrients should meet the needs of this species. It is not terribly demanding but will do best in softer water with CO₂ supplementation.

This species can exhibit highly variable coloration depending on conditions. Moderate lighting will produce dark-green specimens, especially if nitrate is abundant. Light that is too dim or excessive shading will result in the detachment of individual leaves as they melt away from the central stem. Intense, unobstructed lighting will produce a deep-red or maroon-colored specimen. Heavy iron supplementation along with slight nitrogen scarcity can enhance this appearance.

Uses in Aquascaping

B. aubertii is not well suited to nano or small aquariums, as individual plants can easily reach 16 inches in height. In slightly larger aquariums, this species makes an ideal background plant and can be used in the place of Cyperus helferi or many of the Vallisneria spp. The plant can also be employed as a single midground accent specimen in larger aquascapes. This can be particularly striking when exhibiting a reddish coloration on its unusual leaf structure. Mr. Takashi Amano has featured this plant in some of his creations, and it is well suited to his natural style of aquacaping.

Propagation

B. aubertii can be propagated in the aquarium by two methods. Most simply, the central stem and root system can be divided when growth has progressed enough to demonstrate a clear pattern of branching. Growth is slower than in B. japonica, but the method of division is identical.

This plant also flowers readily when allowed to approach the surface. Some hobbyists report flowering success by simply letting a mature specimen float at the surface for a few days. Small seeds will form on modified stalks. Once they turn brown, they can be sown in the aquarium in a position of unobstructed light.