Micranthemum glomeratum aka Pearl Grass
aka Hemianthus micranthemoides
This fast growing plant displays small, bright green teardrop-shaped leaves along a trailing stem. Hemianthus micranthemoides will grow upright if stems are planted densely, or in a spreading pattern when planted sparsely. Intense lighting will encourage it to creep along the substrate, and with regular trimming an easy carpet can be formed.
Hemianthus micranthemoides is simple to grow, requiring moderate to bright light and regular fertilisation. CO2 is beneficial but not required, making this plant a great choice for low tech aquariums.
Hemianthus glomeratus aka Hemianthus micranthemoides often known as baby tears or pearlgrass, is a species endemic to Florida, where it grows abundantly in wet depressions and standing water. Long known in error as the similar Hemianthus micranthemoides, it has chasmogamous (pollinated while fully opened) flowers with acute (pointed) calyx lobes, as opposed to the cleistogamous (non-opening and self pollinated) flowers with obtuse (rounded) calyx lobes of the true H. micranthemoides. The two species also differ in their habitat, with H. micranthemoides being a specialized plant of tidal rivers. Historically, H. micranthemoides grew in appropriate habitat from Virginia to New York, but has not been seen alive since 1941 and may actually be extinct.
H. glomeratus is an undemanding plant with three to four leaves per whorl, requiring only ample lighting in an unshaded location (1.75 watts per gallon with power compacts or more). When lit well, this plant will become very bushy, and the stems will grow at an angle above the substrate. Poorly-lit stems will grow straight up and seem leggy. This plant is an excellent candidate for well lit non-CO2aquaria, although CO2 does promote faster and bushier growth. Although not too picky about fertilization, the plant does appreciate regular doses of nitrate and of an iron/micronutrient mix. High levels of PO4 (1.5-2 ppm) seem to encourage larger, more robust stems and faster growth. This plant is highly sensitive to fish medications such as erythromycin and tryptaflavin and even to nylon fabric.
H. glomeratus is simple to propagate; simply snip off a stem from the bush and replant into the substrate. It is easiest to prune the plant by cutting off the growing tips with a pair of scissors, using a fine net to collect all the leaves and pieces of stem that float upward.
This plant is very versatile for aquascaping purposes. The plant can be used as a foreground plant by planting individual stems horizontally along the substrate and providing ample amounts of power compact, metal halide, or T5 lighting. The plant can also be planted normally and, after repeated prunings, form an impressive bush in the midground or even in the background. Due to its small leaf size, this plant is highly suitable for nano planted aquascapes