Well, I won't list my entire want list as it is 500+ entries, so here is the top ones. I know its still a long list, maybe I'll still try to thin it down a bit. (it is hard to cut down a list of 500+ wants. :)
So far almost only flowers:
Adonis species
Anemone blanda
Anemone sylvestris
Any Erythronium
Any Galanthus/snowdrop
Any Trillium
Aquilegia: alpina, caerulea , Songbird-Series Mix, chrysantha, coerulea, discolor, fragrans, glandulosa, any columbine with green flowers or yellow or variegated leaves.
Arisaema - any except triphyllum
Asclepias tuberosa
Calopogon tuberosus
Corydalis, all none weedy species
Crocosmia
Cyclamen coum, Cyclamen hederifolium, Cyclamen purpurascens
Daphne mezereum
Delosperma cooperi
Delphinium elatum
Dicentra canadensis
Dicentra cucullaria
Dicentra eximia
Dicentra formosa
Dicentra spectabilis (bleeding-heart)
Dodecatheon meadia
Epimedium
Eranthus hymalis
Eryngium yuccifolium 'Kershaw Blue'
Fritillaria meleagris
Gentiana - any perennial types
Gladiolus nanus, or normal perennial gladiolas
Hellebores - any except foetidus
Hymenocallis caroliniana
Iris reticulata
Japanese maple
Jeffersonia dubia
Liatris
Lilium canadense, or martagon
Lilium michiganense
Paeonia ostii - or any species peony.
Papaver orientale - non-orange
Phlox
Primula - any Primula
Pulsatilla - any
Thalictrum rochebruneanum
Tricyrtis - any
Viola pedata
Plants for fruits etc.
Allium tricoccum
Armoracia rusticana
Lonicera caerulea
Elaeagnus multiflora
Pinus koraiensis (pine nut)
