Plant guide · Algae and cyanobacteria
Chara (muskgrass) (Chara species)
A branched alga that looks like a rooted plant. Gritty to the touch and musky when crushed, it is common in Pennsylvania's hard-water ponds.
Also called: muskgrass, stonewort
Some blooms are toxic. Keep people and pets out of discoloured or scummy water and report suspected harmful algal blooms (see fact).
What it looks like
- Looks like a rooted underwater plant, with whorls of branches coming off a main stem.
- Branches are ridged and crusted with lime (calcium carbonate), so it feels gritty.
- A musty smell when crushed gives it the name muskgrass.
- Prefers hard, alkaline water.
Easily confused with
- Nitella: a close relative with smooth, translucent green branches, found in softer, more acidic ponds.
- Coontail and other submerged plants have true leaves; chara does not.
Good and bad for your pond
- Usually good for a pond: waterfowl eat it, insects graze on it, and its root-like rhizoids hold bottom sediment and keep water clear.
- It can grow thick enough to be a nuisance.
Native or invasive?
Algae: common in Pennsylvania ponds. A natural, common alga in Pennsylvania ponds and lakes.
Do grass carp eat it?
Grass carp eat it
Grass carp eat it: PFBC lists chara (muskgrass) among their preferred foods. Grass carp prefer submerged plants like pondweeds, elodea and coontail; they rarely control algae mats or lilies.
Checked Oct 4, 2026 · Source: Using Grass Carp to Control Aquatic Plants (updated May 19, 2025) This may be outdated
Control options
Prevention first
Penn State Extension's advice for every nuisance plant and algae problem starts with nutrients: overgrowth is a symptom of excess phosphorus and nitrogen from sources such as barnyards, crop fields, septic systems, lawns and golf courses. Cutting fertilizer near the pond, maintaining septic systems, diverting nutrient-rich runoff and keeping a vegetated buffer strip are the long-term fixes; without them, control becomes a yearly chore.
Checked Oct 4, 2026 · Source: Filamentous Algae (updated May 19, 2025) and the companion Penn State plant fact sheets This may be outdated
Remove it by hand or machine
Pulling, raking or cutting works, but only for a while: it regrows from spores and fragments. Pile removed material away from the pond.
Biological options
Grass carp, with a PFBC permit: PFBC grass carp permit needed for each waterbody before buying or stocking; $85 fee, returned if denied.
Checked Oct 4, 2026 · Source: 58 Pa. Code § 71a.10, Triploid grass carp This may be outdated
Chemical options (permit first)
Any herbicide or algaecide in a pond needs a joint DEP/PFBC Chapter 91 permit first, at any amount. Only products registered with the U.S. Environmental Protection Agency and with the Pennsylvania Department of Agriculture, and labeled specifically for aquatic use, can be listed on the Chapter 91 permit application. Treat in sections, early in the season: decaying plants can strip oxygen and kill fish.
Checked Oct 4, 2026 · Sources: Water Quality Permitting for Pesticide Applications in Pennsylvania: FAQ (rev. Feb 21, 2025), FAQ #2, #3, #8, #10, #11, #28, #29; Permit Requirement for Use of an Aquatic Herbicide in Ponds (updated Sep 8, 2025); Pond Management (FAQ: controlling submerged vegetation) This may be outdated
Follow the product label; the label is the law. A Chapter 91 permit is required before any herbicide or algaecide goes in a pond (see fact). Consider a licensed applicator.
Sources
- Chara and Nitella (Penn State Extension)
- Controlling Nuisance Aquatic Plants and Algae in Farm Ponds (Penn State Extension)
- Using Grass Carp to Control Aquatic Plants (Penn State Extension)
Checked Oct 4, 2026