Hemianthus micranthemoides is also known to aquarists as Micranthemum micranthemoides, and it’s also known as Pearl Weed and Baby Tears or Pearl Grass…so many names for a small and versatile stem plant!
AND…It’s also known as Nuttall’s Mudflower, at least according to the USDA! That species happens to be a native of the eastern United States. Some sources suggest this species may be extinct in the wild, existing only in the aquarium trade now, with one source suggesting the last wild plant was seen in the 1940s. However, even this bit of “fascinating background” leads to a more interesting twist.
Author Dr. Jordan Teisher suggesting that in fact, all the “Pearl Weed”, or H./M. micranthemoides we have in the aquarium trade is actually a different species that is native to Florida–Hemianthus glomeratus! Take it one step further, and Chistel Kasselmann assigns this plant to the taxon Micranthemum glomeratus, noting that Hemiathus was merged into the genus Micranthemum after phylogenic analysis! As with so many plants in the aquarium trade and elsewhere, the taxonomy and identifications here are simply a mess!
Being a low-growing stem plant, it’s quite versatile; stems can range anywhere from 2″ to 8″ tall, depending on the source, but you can trim this plant to any height you desire. Generally considered an easy to moderate plant, and requiring at least moderate light; brighter light should help give less leggy, more compact growth.
Kasselmann notes that this aquarium plant can also be used as a foreground paludarium plant, and I suspect it can have vivarium applications as well!
About Tissue Cultured Plants
In-vitro or tissue culture methodologies are used to create genetic clones of countless forms of plant life from orchids to hostas and yes, more recently aquarium plants. Tissue cultures are free of algae and pests, grown in a lab from clean, micro propagated plant material. Tissue cultures are “matured” when offered for sale, and should be used upon arrival if possible…wait too long and they’ll decline. While aquarium and aquascaping applications are the main target of tissue culture offerings, many of the plants available via tissue culture can also be used in emersed or even paludarium and vivarium-type conditions.
To use your tissue culture, simply rinse all the culture media from the plants. You can divide up the culture into many smaller pieces, or in the case of some types, individual small plants are readily apparent and can be utilized individually.