The deck has 80 cards in ten different colors, with each color featuring a different species of tree; each color has cards numbered 1 through 8, and the number of colors used depends on the number of players. Players start with a hand of seven cards. On each turn, a player draws two cards (from the deck or one or more of the discard piles), lays a card on the table as part of her arboretum, then discards a card to her personal discard pile.
When the deck is exhausted, players compare the cards that remain in their hands to determine who can score each color. For each color, the player with the highest value of cards in hand of that color scores for a path of trees in her arboretum that begins and ends with that color; a path is a orthogonally adjacent chain of cards with increasing values. For each card in a path that scores, the player earns one point; if the path consists solely of trees of the color being scored, the player scores two points per card. If a player doesn’t have the most value for a color, she scores zero points for a path that begins and ends with that color. Whoever has the most points wins.