Micranthemum Glomeratus (Pearl Weed) Vitro Culture

Want one plant that can be a carpet or a hedge? Pearl Weed does both — trimmed low it creeps sideways into a fine bright-green mat, left alone it grows upright into a bushy column. Few plants change role that completely depending on how you cut them.

You may know it as Micranthemum micranthemoides. That is the same plant — see the note below.

What You’ll Receive

Sold as loose Vitro Culture® plantlets in a 4-inch sealed bag:

• Vitro Culture® Bag: Contains a dense portion of Micranthemum glomeratus, ready to rinse, acclimate, and plant in your aquarium.

Plant Profile

• Common name — Pearl Weed, also known as Pearl Grass, Baby Tears
• Scientific name — Micranthemum glomeratus
• Also known as — Micranthemum micranthemoides, Hemianthus micranthemoides
• Placement — Foreground to midground
• Mature height — 2–4 in trimmed, taller left upright
• Growth rate — Medium

Why two scientific names?

Pearl Weed has been sold as Micranthemum micranthemoides (also written Hemianthus micranthemoides) for decades, and most aquarists still know it by that name. It is worth understanding why that name is no longer accurate.

Micranthemum micranthemoides was a real species, native to the tidal river margins of the eastern United States from New Jersey to Virginia. It has not been recorded in the wild since the 1940s and is now considered extinct.

The plant that spread through the aquarium hobby under that label is a different, living species — Micranthemum glomeratus, from the southeastern United States. The mislabelling has followed the plant through the trade ever since.

So the plant you receive is Micranthemum glomeratus: the same plant you have always bought as Pearl Weed, correctly named. No genuine M. micranthemoides is in cultivation anywhere.

Care

• Difficulty — Beginner
• Light — Medium. More light gives tighter, denser growth
• CO₂ — Not required. It carpets faster with it, but does not need it
• Water — 68–82°F · pH 6.0–7.5
• Substrate — Not required, but a nutrient substrate visibly helps
• Growth habit — Amphibious. Also grows emersed in paludariums
• Propagation — Stem cuttings

Grower’s Notes

• Trimming decides what plant you get. Cut it back repeatedly and it branches sideways into a carpet. Leave it and it climbs into a soft green bush. Decide which you want before planting, because the two need different spacing.
• Don't bury the stems deeply. The stems are fine and rot if pushed too far into substrate — plant just enough to hold them.
• Replant the trimmings. Cut tops root readily, so one cup fills a foreground over a couple of months at no extra cost.
• Tissue culture plantlets are grown emersed and convert over two to three weeks. Rinse the gel off completely before planting or it clouds the water and feeds algae.

Want to go deeper? Read our complete Micranthemum Care Guide.

Notes

• Product images show mature, submerged growth for reference. Tissue culture plants may appear different upon arrival due to emersed growth in sterile conditions. Gradual acclimation is recommended. Avoid burying delicate stems too deeply into the substrate.
• Never release aquarium plants into natural waterways.

At a glance

• Free shipping on orders of $150 or more (after discounts) within the contiguous United States, by USPS.
• Free thermal protection is included with every shipment, all year round.
• Processing: most orders leave us within 1 to 2 business days. Tracking is emailed when your order ships.
• USPS (2 to 5 business days) ships Monday through Saturday.
• UPS 2nd Day Air® ships Monday through Wednesday. Order by Tuesday at 6:00 AM Pacific Time for same-week delivery.
• UPS Next Day Air® ships Monday through Thursday. Order by Wednesday at 6:00 AM Pacific Time for same-week delivery.
• Alaska, Hawaii, Puerto Rico, Guam, the U.S. Virgin Islands and military addresses ship by USPS at a flat rate shown at checkout.
• Weather holds: during extreme heat or cold we may hold live orders until it's safe to ship.
• We ship within the United States only.

Please bring live plants indoors and unpack them the day they arrive. Every live order is covered by our 24-Hour Live Arrival Guarantee.

The complete rules, including lost packages and address issues, are in our Shipping Policy. If anything conflicts, that policy applies.

Every live order is backed by our 24-Hour Live Arrival Guarantee. If a plant arrives dead, we'll make it right.

How it works

• Tell us within 24 hours of the delivery time on your tracking.
• Send photos of the affected items in their original, unopened packaging, plus a photo of the shipping label, to hello@aquariumplantsfactory.com with your order number.
• We'll make it right with a replacement, store credit or refund for the affected item.

Good to know

• Some melting or yellowing as plants adjust from greenhouse to aquarium life is normal. They regrow from healthy roots and rhizomes.
• Please bring your package indoors and unpack it the day it arrives.
• Free promotional items and shipping charges are not covered.

The complete rules, including what's covered and what voids the guarantee, are in our Returns, Refunds & Live Arrival Guarantee. If anything conflicts, that policy applies.

Please review your state's regulations on restricted plants, as we are committed to not shipping plants that are restricted in your area. Do not release any plants into the wild or waterways, as this can harm local ecosystems by introducing invasive species.

Your cooperation in protecting the environment is appreciated. For continuously updated information, refer to the USDA State Noxious Weed list here.

Thank you for your responsible commitment to environmental preservation.