Catchweed, catchweed bedstraw, catchweed burrs
Scientific name: Galium aparine L.[47]
Description: A plant with fuzzy green balls on long stems.[48]
Location: It is common in hedges and other low, shrubby vegetation.[47] Found in ThunderClan territory.[49]
Usage: The burrs are put on the pelt where poultices are.[48]
Effect: Stops poultices from being rubbed off without hurting the skin.[48]
In Moth Flight's Vision, Moth Flight mentions that Cloud Spots had taught her how to use catchweed.[49]
In The Sight, Mothwing recommended this herb to Jaypaw in to help stop Stormfur's poultice from getting rubbed off.[48]
Catmint

Catmint.jpg
Catmint, catnip
Scientific name: Nepeta racemosa[50]
Description: A leafy and delicious-smelling plant.[20] Has gray-green leaves, stem is hairy, and has purple flowers.[50] Is easily killed by frost.[51] Looks like nettles, but doesn't sting.[52]
Location: Rarely found in the wild; mostly found in Twoleg gardens.[20] Can specifically be found in the Twolegplace near ThunderClan's forest territory.[53] Can also be found in WindClan territory by the lake.[54] Located in a Twoleg barn near WindClan's forest territory during the early days of the Clans.[55] Found in the abandoned Twoleg nest.[56] Thrives in areas with dry soil and is very tolerant of dryer conditions.[50]
Usage: Eaten.[57]
Effect: Best remedy for the deadly greencough, which kits and elders usually catch in the season of leaf-bare. Can also be used for whitecough.[20] Can be considered dangerous in extremely high dosages.[50]
In Secrets of the Clans, Cloudspots is revealed to have discovered catmint.[58] It is also mentioned to be the best cure for whitecough and greencough.[20]
In Moth Flight's Vision, Micah explains to Moth Flight what catmint is. Micah claims that he has had dreams of bringing catmint to help a sick kit.[52] Star Flower finds this out, and pleads with Clear Sky to allow Micah to treat Tiny Branch in an attempt to save the small kit.[59] Moth Flight later uses catmint to help cure Rocky, who has fallen ill.[55]
In Bluestar's Prophecy, Featherwhisker mentions that it is better to gather catmint once the dew has burned off of the plants. This makes it easier to gather dryer sprigs so they do not rot while in the medicine cat den.[60]
In Sunset, Leafpool travels to the abandoned Twoleg nest near ShadowClan territory, and returns with catmint.[56]
In Long Shadows, Jaypaw finds out from Brightspirit, a StarClan cat, that WindClan has a supply of catmint.[61] Jaypaw eventually sends Lionblaze to find it,[62] and while he gets into a brief quarrel with Heathertail, he eventually takes the catmint and leaves.[63]
Celandine

Celandine.jpg
Celandine, celandine poppy, greater celandine
Scientific name: Stylophorum diphyllum[64] or Chelidonium majus[65]
Description: Yellow flower with four petals. Celandine poppy have bigger petals, whereas the greater celandine are smaller.[64][65]
Location: Grows on both ThunderClan[66] and RiverClan's territories, but possibly grows better on ThunderClan land.[67]
Usage: Crushed into juice and trickled into the eye.[68]
Effect: Soothes weakened[67] or damaged eyes.[68]
In Midnight, Cinderpelt sends Leafpaw to look for celandine. She is joined by Sorreltail,[66] and the two ThunderClan cats meet up with a RiverClan patrol.[69] They exchange words, and Leafpaw gives Hawkfrost and Mistyfoot some of ThunderClan's celandine to give to Mothwing.[67]
In Sunrise, Littlecloud suggests to Mothwing to drip a small amount of a celandine juice into Petalkit's eye, as the kit had gotten a thorn stuck in it.[68]