This is an improved version of Kems list.
I have found this list here: http://xxsecrets.proboards.com/index.cgi?board=canreads&action=display&thread=479 and some from http://warriors.wikia.com/wiki/Medicine
Ill edit this list with more comments

Name: Alder
Parts: bark
Purpose: a good and easy cure for a toothache
Used For: toothache

Name: Alfalfa
Parts: flowers, leaves, petals, sprouts
Purpose: detoxifies body; good for bleeding-related disorders, colon and digestive disorders.
Used For: bleeding and indigestion
Comments: sprouts are especially effective.

Name: Anise
Parts: seeds
Purpose: aids digestion; clears mucus; combats infection; promotes milk production.
Used For: nursing queens; colds; wounds in order to prevent infection

Name: Ash
Parts: seeds, shoots
Purpose: seeds help ease pain; shoots can be chewed and spit on a wound in order to resist poison from snakebite
Used For: snakebite; pain

Name: Aspen
Parts: bark
Purpose: relieves stress and soothes restlessness and anxiety
Used For: overly anxious cats

Name: Astragalus
Parts: roots
Purpose: digestion; increases metabolism; promotes healing; provides energy.
Used For: colds; flu; indigestion; fatigue
Comments: also called huang qi. DO NOT GIVE IN THE PRESENCE OF A FEVER!!!

Name: Bayberry
Parts: root bark
Purpose: clears congestion; reduces fever; stops bleeding
Used For: colds; fever; bleeding

Name: Belladonna
Parts: full plant
Purpose: POISONOUS
Used For: POISONOUS
Comments: Also known as Deadly Nightshade

Name: Bilberry
Parts: entire plant
Purpose: eases inflammation; helps with stress and anxiety
Used For: swelling; stress; anxiety
Comments: also known as blueberry

Name: Bindweed
Parts: entire plant
Purpose: Fastens sticks to broken legs to keep them in place

Name: Birthwort
Parts: roots, aerial parts
Purpose: anti-inflammatory; antibiotic; helps heal wounds
Used For: swelling; infection; wounds
Comments: Should not be used if avoidable; highly dangerous

Name: Black Cohosh
Parts: roots
Purpose: reduces mucus production; aids in birth; helpful with poisonous snakebite; relieves pain
Used For: colds; birth; snakebite; pain
Comments: also known as black snakeroot. CAUTION: do not use during pregnancy unless in labor

Name: Black Willow
Parts: leaves
Purpose: contains natural aspirin- reduces pain and swelling
Used For: pain; swelling
Comments: internal use; must be swallowed

Name: Blessed Thistle
Purpose: increases appetite; alleviates inflammation; aids milk flow
Used For: hunger problems; swelling; nursing queens
Comments: Caution- handle with care

Name: Boneset
Parts: flower petals, leaves
Purpose: relieves congestion; loosens phlegm; calms the body
Used For: colds; stuffiness; calming
Comments: increases perspiration; acts as a laxative; also known as white snakeroot. CAUTION- do not use long-term

Name: Broom
Parts: leaves
Purpose: makes a good poultice for broken legs and wounds
Used For: broken bones; wounds

Name: Burdock
Parts: roots, seeds
Purpose: stimulates immune system; aids in fighting infection
Used For: battle wounds; also good for rat bites

Name: Catnip
Parts: leaves
Purpose: controls fever; aids digestion and sleep; relieves stress; stimulates appetite
Used For: colds; flu; hunger problems; anxiety; sleeping disorders; Greencough

Name: Chamomile
Purpose: anti-inflammatory; appetite stimulant; digestive aid; sleep aid
Used For: swelling; hunger disorder; constipation; sleeping disorder
Comments: do not use for long periods of time

Name: Chickweed
Purpose: reduces mucus buildup in the lungs
Used For: colds; coughs
Comments: also called starweed

Name: Comfrey
Parts: leaves, roots
Purpose: speeds healing of wounds
Used For: wounds
Comments: also called knitbone. Do not use in pregnancy. May cause liver problems.

Name: Dandelion
Parts: leaves, roots, tops
Purpose: increases production of bile
Used For: stomach acid problems; eating disorders; indigestion

Name: Echinacea
Parts: leaves, roots
Purpose: useful for colds, flu, and snakebite
Used For: colds; flu; snakebite
Comments: also called coneflower

Name: Elder
Parts: berries, flowers, inner bark, leaves, roots
Purpose: eases constipation; fights inflammation; lowers fever
Used For: constipation; swelling; fever
Comments: stems are very toxic

Name: False Unicorn Root
Parts: roots
Purpose: helps prevent miscarriage
Used For: pregnancy/kitting
Comments: also called helonias

Name: Feverfew
Parts: bark, dried flowers, leaves
Purpose: stimulates appetite; reduces fever; helps control pain
Used For: fever; headaches; pain; lack of appetite
Comments: should not be taken during pregnancy

Name: Garlic
Parts: bulb
Purpose: Aids in cold and flu problems; digestion problems; good for fighting off disease and infection
Used For: colds; flu; constipation; disease; infection

Name: Ginger
Parts: roots
Purpose: soothes the stomach and reduced fever
Used For: fever; indigestion; nausea; vomiting
Comments: can cause stomach distress

Name: Ginseng
Parts: roots
Purpose: helps with lack of energy; stress
Used For: stress; anxiety; sleeping disorders

Name: Goldenseal
Parts: roots
Purpose: can be used at first sign of symptoms to stop colds, flu, or sore throat from developing
Used For: first symptoms of cold, flu, sore throat
Comments: do not use during long periods of time or during pregnancy

Name: Hops
Parts: berries, leaves, flowers
Purpose: good for anxiety, nervousness, pain, restlessness, shock, stress
Used For: anxiety; nervousness; pain; sleep; shock; stress

Name: Horsetail
Parts: stems
Purpose: good for inflammation; muscle cramps; poultice form to slow bleeding and speed healing of wounds
Used For: swelling; muscle cramps; bleeding; healing
Comments: also called bottlebrush and shavegrass

Name: Juniper
Parts: berries
Purpose: relieves inflammation and congestion; bladder infection; obesity;
poultice made with ragwort leaves- aching joints, but too much will cause a bellyache if swallowed
Used For: swelling; colds; bladder infections; weight loss; cough; bellyache

Name: Kava
Parts: roots
Purpose: mental relaxation
Used For: depression; anxiety
Comments: can cause drowsiness

Name: Lavender
Parts: flowers
Purpose: relieves stress and depression; also good for headaches and chill
Used For: chill; stress; depression; headache

Name: Marigold
Parts: leaves
Purpose: heals cracked pads damaged from cold; counters infection
Used For: cracked pads; bites and wounds

Name: Mustard
Parts: seeds
Purpose: applied externally- chest congestion; inflammation; injuries; joint pain
Used For: congestion; swelling; wounds; joint pain
Comments: can cause skin irritation

Name: Nettle
Parts: flowers, leaves, roots
Purpose: pain reliever
Used For: pain; congestion
Comments: stinging nettle

Name: Peppermint
Parts: flowering tops, leaves
Purpose: enhances digestion; increases appetite; helps alleviate headaches; soothes the stomach
Used For: digestion; chills; diarrhea; headache; nausea; poor appetite

Name: Poppeyseeds
Parts: seeds
Purpose: a natural drug; numbs pain
Used For: pain; deeper slumber
Comments: causes drowsiness

Name: Sage
Parts: leaves
Purpose: dries up milk for end of nursing
Used For: end of nursing of kits

Name: Skullcap
Parts: aerial parts
Purpose: aids sleep; takes edge off of headaches; calms the muscles
Used For: sleeping disorders; headache; anxiety; hyperactivity; muscle cramps; pain; stress

Name: Slippery Elm
Parts: inner bark
Purpose: treats colds, flu, and sore throat
Used For: cold; flu; sore throat
Comments: also called moose elm and red elm

Name: Yarrow
Parts: berries, leaves
Purpose: reduces inflammation; increases perspiration; causes cats to vomit; helps blood clotting; made into ointment- softens pads to aid in healing
Used For: fever; bleeding; cut or cracked pads; emergency retching

Name: YEW
Parts: BERRIES
Purpose: POISONOUS
Used For: DO NOT USE
Comments: DEADLY