Hemianthus glomeratus Care Guide
Hemianthus glomeratus, known as pearl weed, is a versatile bright-green North American stem plant used as carpet, midground bush or background.
Overview
Hemianthus glomeratus is a small-leaved stem plant native to North America. It was long sold under the names Hemianthus micranthemoides and Micranthemum micranthemoides, but the plant common in the hobby was later identified as a distinct species, Hemianthus glomeratus. It forms airy, bright-green bushes.
Taxonomy
- Family: Linderniaceae
- Genus: Hemianthus
- Scientific name: Hemianthus glomeratus
- Former trade names: Hemianthus micranthemoides, Micranthemum micranthemoides
Habitat
Pearl weed grows in the Mid-Atlantic region of the United States, found in still waters, wet pools and ditches, including tidal rivers with gravel or sandy substrates. The true Hemianthus micranthemoides is thought by many botanists to have been extinct in its native range since around 1941.
Aquarium requirements
- Temperature: 22-28 °C (72-82 °F)
- pH: 5.5-7.5
- GH: 2-12 °dGH
- Lighting: moderate to high
- CO2: recommended (best with about 6-14 ppm)
- Placement: midground; can be trained as a carpet
- Maximum height: about 15 cm
Moderate light produces vertical growth with longer gaps between leaves, while high light keeps the plant compact and suitable for carpets. Without CO2 the leaves may form greyish-white lime deposits through biogenous decalcification.
Care and growth
Growth is fast, especially once established, and the plant requires regular trimming to stay dense and healthy. It tolerates a range of substrates including gravel, sand and aquarium soil, but benefits from added nutrients.
Propagation
Pearl weed is propagated from stem cuttings. Trimmed tops are replanted, and the plant also spreads via roots on creeping stems, forming new shoots that thicken the group.