A blossom consists of two components: the character and the flower.Character = Any character from any anime/manga/game you want. Example = Tsukino Usagi, Lina Inverse, Lantis, Tenkawa Akito, Rinoa Heartilly, etc. You MUST have a real character; no Sailor [enter astrological sign here] or characters from a manga/story you are creating.
Flowers = Bascially any flowering plant on the face of the earth. Some examples :: azalea : aster : black-eyed susan : bluebell : buttercup : bleeding heart : basket-of-gold : bouganvillea : catmint : crocus : carnation : crysanthemum : columbine : clematis : daisy : daffodil : dragon's blood : dahlia : forget-me-not : delphinium : freesia : foxglove : gardenia : gentian : gladiolis : geranium : hibiscus : honeysuckle : hollyhock : iris : impatien : jonquil : lavender : ladyslipper : lotus : love-in-idleness : love-lies-bleeding : lily : lilac : loosestrife : lotus : marigold : magnolia : morning glory : monkshod : mallow : narcissus : orchid : oleander : periwinkle : petunia : pink : phlox : pansy : poppy : primrose : peony : posy : Queen Anne's Lace : rose : red-hot poker : sundrop : snowdrop : sunflower : snapdragon : spiderwort : soapwort : tiger lily : tulip : tuberose : violet : vinca : wisteria : water lily : yarrow : zinnia : and many more!
Flowering trees and plants = cherry(sakura) : apple : plum : pear : peach : sweet pea.
For further listing of flowers, please try Plant Dictionary
Also, a "red rose" and a "black rose" are still both roses. You can specify a color if you want, but it's still the same flower. So "Hikaru :: Red Rose" is the same as "Hikaru :: Black Rose". To see which combos have been taken, click here.