Once per turn: You can choose a number from 1 to 3, then excavate that many cards from the top of your Deck, send any excavated Plant-Type monsters to the Graveyard, also place the other cards on the bottom of your Deck in any order. If this card is excavated from the Deck and sent to the Graveyard by a card effect: You can target 1 other Plant-Type monster in your Graveyard; place that target on top of your Deck.
2400 attack 1 tribute monster, which can be easily summoned in a plant deck if you use cards like Rose Lover.
Can choose to excavate 1-3 cards, which is good in a Sylvan deck.
When excavated, you can return a Plant-type monster from your grave to the top of the deck. Returning a card like Sylvan Komushroomo, or Sylvan Marshalleaf can be really good if you can excavate right away.
Weak when switched to defense since he has low defense.
Excavated non plant type monsters will get sent to the bottom of the deck.
Sylvan's playstyle is to excavate cards from the deck and send them to the grave to activate their effects. Komushroomo lets you excavate 1-5 cards so you can get other Sylvan monster's effects, or send a Rose Lover so you can special summon Guardioak and be immune to traps for a turn. Magical Merchant can work in a Sylvan deck as well, but it has a chance to fail if you have some spells and traps in the deck.
Rose Lover is pretty good in a Sylvan deck since it will also get sent to the graveyard if it's excavated from your deck, as well as World Carrotweight Champion, and they both have effects that can activate from the graveyard. You can also use Carrotweight from the grave to send a Rose Lover to the grave from your hand to special summon Carrtoweight, and activate Rose Lover from the grave to special summon Guardioak.
Pick up a card / Sends from your Deck to your Graveyard / Activates from your Graveyard / Returns from your Graveyard to your Deck / Excavates / Sends excavated cards to the Graveyard / Places excavated cards on the bottom of the Deck