Herb

An Herb is a consumable item in the Golden Sun series. Like most consumable items, each party member can hold up to 30 herbs in a single inventory slot. When used, an herb restores 50 Hit Points to a single party member. Herbs can be bought for 10 coins and sold for 7 coins.

Locations
Being the simplest HP-restoring item in the series, herbs can be found almost everywhere. Almost every item vendor sells them and many party members have some with them when they first join the player. Also, many monsters drop herbs, and they can be found in a number of chests, jars, barrels, etc., especially early in a game.

Golden Sun Herbs
In the original Golden Sun game, herbs can be bought from the item vendors in Vale, Vault, Bilibin, Imil, Kolima, Xian, Altin, Kalay, Tolbi, Lunpa, Suhalla, and Lalivero.

Herbs are dropped by Vermin, Mad Vermin, Bats, Slimes, Oozes, Slime Beasts, Rats, Armored Rats, Worms, Zombies, and Skeletons.

Herbs can also be found in the following locations:
 * A treasure chest deep within Sol Sanctum, just before entering the Sol and Luna rooms.

The Lost Age Herbs
In Golden Sun: The Lost Age, herbs can be bought from the item vendors in Daila, Madra, Alhafra, Garoh, Mikasalla, Naribwe, Kibombo, Yallam, Apojii Islands, Izumo, Champa, Shaman Village, Contigo, Loho, and Prox.

Herbs are dropped by Ruffians, Wild Wolves, Mad Vermin, Giant Bats, Oozes, Rats, Dinos, and Skeletons.

Herbs can also be found in the following locations:
 * A treasure chest in Venus Lighthouse, during the prologue when the player controls Jenna
 * In a jar in Daila, on a cliff to the right of the sanctum
 * In a green jar in the house in the south-east of Mikasalla
 * Under the weeds in the Apojii Islands (by where the river meets the ocean)
 * On the left side of the courtyard in Lemuria (by using Scoop)
 * On the right side of the courtyard in Lemuria (by using Scoop)

Dark Dawn Herbs
In Golden Sun: Dark Dawn, herbs can be bought from the item vendors in Patcher's Place, Carver's Camp, Harapa, Passaj, Kaocho, Te Rya, Belinsk, Border Town, Port Rago, Saha Town, Harun Village, Yamata, Tonfon, and Champa Camp.

Herbs are dropped by Flutter Seeds, Rats, Oozes, Slime Beasts, Kobolds, Goblins, Goblords, and White Wolfs.

Matthew has two herbs in his inventory at the start of the game, and Karis, Tyrell, Rief, and Sveta all join the party with a single herb.

Herbs can also be found in the following locations:
 * A pot outside Lookout Cabin. Upon leaving the cabin, walk down the steps to the left. The herb is in the lower-left pot.
 * A treasure chest in Tanglewood, located by the pond in the first area.
 * A barrel in the main building of Patcher's Place. There are two back rooms to Patcher's shop. Two barrels are located in the back room on the bottom floor. The herb is in the lower-right barrel.
 * A jar near the end of the Goma Highlands Road. Starting from Carver's Camp, take the upper entrance to the Highlands (requires use of the Move Psynergy). Two jars are to the north of the entrance, with the rightmost jar holding the herb.
 * A barrel at Carver's Camp. Upon entering the house next to the gondolas, three barrels and jars are lined up to Matthew's immediate right. The middle barrel houses the herb.
 * A wooden box in Harapa. There are four buildings in the central plaza. The lower-right building (south of the armor and item vendors and the inn) contains several crates. The herb is in the box farthest to the right.
 * A barrel in Passaj. Houses in the western half of the city are connected by a tunnel system. The main tunnel has a barrel and a jar, the former of which shelters the herb.
 * A jar in Kaocho Palace. Excluding the throne room, the palace has two back rooms. The room to the right has two jars, and the left jar holds the herb.
 * A barrel in Ayuthay. Immediately upon entering there are paths to the right and left. Both are dead ends, but an herb is hiding in a barrel at the end of the left path.
 * The Clouds of Passaj have two "basement"-style rooms. The second one (beneath the fourth "normal" room) is split into two areas. Two access the second area, touch one of the thunderclouds surrounding the giant tornado that leads to the next normal room. Once here, cast Whirlwind on the nearby flowers. An herb is growing beneath the upper-right one.
 * A barrel in Belinsk. The building with the sanctum has three floors, and the top floor houses two barrels. An herb is in the upper-left barrel.
 * Another herb is held in the wooden box outside the inn of Port Rago.
 * A jar in Kolima Village. The southeast house is an item shop that sells Dream Leafs. Just outside is two jars and a wooden crate. The lower jar contains the herb.
 * The jar to the right of Harun Village's inn holds an herb.
 * An herb is hidden in the upper-right-most jar in Yamata City's item/equipment shop.
 * Another herb can be found in a barrel in Tonfon, located along the southern edge of the platform between the main walkway and the weapon and armor shop.
 * The upper-left-most crate surrounding the inn of Champa Camp houses yet another herb.

Analysis
Herbs are the first HP-restoring item available in every Golden Sun game, making them a valuable asset early on when Psynergy Points are low, limiting the usefulness of healing Psynergy. By the end of any given game, however, players will have access to many other HP-restoring alternatives, making herbs effectively obsolete: nuts, vials, and potions all restore far more HP than herbs; increased PP reserves allow for near-reckless use of healing Psynergies like Potent Cure and Pure Wish; and many pieces of equipment gradually restore Hit Points in battle, such as the Mysterious Robe and Gloria Helms.

At first glance it appears that, near the end of a game, herbs will simply take up inventory space that could be put to better use. While that is generally true - especially in the middle of a battle, when each item used takes up that Adept's action for the turn - that does not mean that herbs are completely useless. As far as HP-restoring items go, herbs are by far the most cost-effective choice, restoring five times as many Hit Points as the number of coins spent on them. This makes them an inexpensive alternative to inns when healing minor wounds. They can also be used in large quantities between battles when a player is trying to conserve PP: a full inventory of 30 herbs will restore 1500 Hit Points. While not nearly as effective as other items (only three vials will restore the same amount of HP), it is still the cheapest alternative (three vials cost 1500 coins, whereas 30 herbs cost only 300 coins).

Trivia

 * Before Golden Sun: Dark Dawn, herbs were the only non-Artifact HP-restoring item that cost fewer coins than the number of Hit Points they restored.