(Scientific Name: Equisetum resonus | Common Nicknames: The Chime-Field, Silver Points | Charles’s Ledger: Variable-F07)
Botanical Profile: The Acoustic Grid
Habitat: Grows in segmented, perfectly straight rows within the mineral-rich "Hard-Waters" of the Arkansas River.
Crystalline Structure: The stalks pull silica and metallic salts from the riverbed, creating a body as clear and brittle as industrial glass.
Sonic Mimicry: The hollow segments act as natural resonators. They catch vibrations from wind, water, or footsteps and amplify them across the entire reed network.
The Chime-Field: In high winds, the reeds collide to create a crystalline chiming sound. While beautiful, this acoustic "noise" is used by predators to mask their movement.
Charles’s Note: "The Echo Reeds are the river’s nervous system. They turn every footfall into a broadcast. If you don't know the pitch of the reeds you're standing in, the marsh already knows where you're going."
Physical Characteristics: The Silver Point
Brittle & Sharp: The stalks do not bend; they shatter. The resulting shards are as sharp as obsidian and almost invisible in the water.
Mineral Grain: The clear walls are reinforced with mineral deposits, giving them a high-resonance frequency that can be felt as a physical hum when touched.
Hollow Interior: The segmented chambers are lined with silica-rich fibers that act as a natural, biological filtration system.
Performance Specs: Material Science
Echo Daggers: A mature segment can be snapped to create an "Echo Dagger." Because of its high resonance, a strike against bone transmits a vibration that can temporarily paralyze a limb or disrupt a nervous system.
Acoustic Mapping: Village scouts use arrays of these reeds to "listen" to the marsh. By monitoring the pitch of the chimes, they can detect the heavy footfalls of an Ironback or the displacement of a Tyrant miles away.
Pressure Popping: As Charles noted in his audit of the Flesh Vise, a sliver of Echo Reed is the perfect tool for piercing hydraulic segments due to its rigidity and needle-sharp point.
Charles’s Audit: The Acoustic Constant
"The Echo Reeds are a network of math, tuned by the river itself. Step wrong and the chimes will tell everything in the marsh your business. I don’t touch them without measuring their pitch, or the marsh will warn the predators loud enough to feel in my bones. Two, three, five, seven... respect the silence of the glass." — Charles, The Analyst
Chime-Field Masking: While within an Echo Reed patch during high winds (The Chime-Field), all creatures have Disadvantage on Perception checks relying on hearing. Stealth checks gain a +2 bonus.
Glass Shards: If a creature is knocked prone or forced to move through shattered reeds, they take 1d6 piercing damage.
The Echo Strike: A successful hit with an Echo Dagger deals 1d4 piercing damage. The target must succeed on a DC 12 Constitution save or have its movement speed reduced by 10 feet until the end of its next turn due to harmonic vibration.
Natural Filter: A character can use an Echo Reed stalk to drink safely from stagnant water, granting Advantage on saves against waterborne toxins or the "Neon Rot."