How Do You Get the Gracidea Flower in Pokemon: SoulSilver?

Attend a live Pokemon event. These events are listed on the Serebii event database or on the official Pokemon web site. Bring your Nintendo DS and "Pokemon: Platinum" with you. Make sure the event is for the item "Oak's Letter," which you will be given when you attend.

Travel along Route 224 in "Pokemon: Platinum." The route will be longer since you now have Oak's Letter. Enter the patch of flowers at the end of the route, and you will see a level 30 Shaymin awaiting you. Approach it to enter battle.

Weaken Shaymin and use a Pokeball to capture it. Go to the Oreburgh City Pokemon Center and talk to the Wi-Fi club representative to get the Pal Pad. Enlist a friend to play "Pokemon: Soul Silver" on another DS. Be sure to sit close together. Your friend should repeat this process to earn the Pal Pad.

Swap "Friend Codes" with your friend. You can find your friend code by selecting "X" and then pick "Bag." Press "A" and click on the key symbol to open the "Key Items" listing. Select "Pal Pad" and press "A." Press "A" to use the item. Press "A" when "Code" is highlighted to view your code.

Repeat Step 4, but highlight "Register Friend Code" instead of "Code" and press "A." Type in your friend's Friend Code and have him do the same with your code.

Travel to the second floor of any Pokemon Center. Speak to the woman in the middle of the room to enter the "Union Room." Your friend should also travel to any Pokemon Center and enter the Union Room.

Approach your friend while in the Union Room to initiate trading. Select "Shaymin" from your menu and press "A" to accept the trade. Wait for your friend to accept the trade. Save your games. Turn off "Pokemon: Platinum."

Travel to Goldenrod City in the Johto region in "Pokemon: Soul Silver." Enter the Flower Shop. You should have Shaymin in your party. Speak to the owner. You will be given the Gracidea Flower, which enables Shaymin to change into a different form.