Unsafe plants for birds
 
Harmful Plants (first source)
Amaryllis - bulbs
American Yew
Avocado
Azalea - leaves
Balsam Pear - seeds, outer rind of fruit
Baneberry - berries, root
Bird of Paradise - seeds
Black Locust - bark, sprouts, foliage
Blue-green Algae - some forms toxic
Boxwood - leaves, stems
Buckthorn - fruit, bark
Buttercup - sap, bulbs
Caladium - leaves
Calla Lily - leaves
Castor Bean - also castor oil, leaves
Chalice Vine/Trumpet vine
Christmas Candle - sap
Clematis/Virginia Bower
Coral Plant - seeds
Cowslip/Marsh Marigold
Daffodil - bulbs
Daphne - berries
Datura - berries
Deadly Amanita
Death Camas
Delphinium
Deffenbachia/Dumb Cane - leaves
Eggplant - fruit okay
Elephants Ear/Taro - leaves, stem
English Ivy berries, leaves
English Yew
False Henbane
Fly Agaric Mushroom - Deadly Amanita
Foxglove - leaves, seeds
Golden Chain/Laburnum 
Hemlock - also water the plant is in
Henbane - seeds
Holly - berries
Horse Chestnut/Buckeye - nuts, twigs
Hyacinth - bulbs
Hydrangea - flower bud
Indian Turnip/Jack-in-Pulpit
Iris/Blue Flag - bulbs
Jack-in-the-Pulpit
Japanese Yew - needles, seeds
Java Bean - lima bean - uncooked
Juniper - needles, stems, berries
Lantana - immature berries
Larkspur
Laurel
Lily of the Valley - also water the plant is in
Lobelia
Locoweed 
Lords and Ladies/Cuckoopint
Marijuana/Hemp - leaves
Mayapple - fruit is safe
Mescal Beans - seeds
Mistletoe - berries
Mock Orange - fruit
Monkshood/Aconite - leaves, root
Morning Glory
Narcissus - bulbs
Nightshade - all varieties
Oleander - leaves, branches, nectar
Philodendron - leaves and stem
Pointsetta - leaves, roots, immature
Poison Ivy - sap
Poison Oak - sap
Pokeweed/Inkberry - leaf,root,young berries
Potato - eyes, new shoots
Privet
Rhododendron
Rhubarb - leaves
Rosary Peas/Indian Licorice - seeds
Skunk Cabbage
Snowdrop
Snow on the Mountain/Ghostweed
Sweet Pea - seeds, fruit
Tobacco - leaves
Virginia Creeper - sap
Water Hemlock 
Western Yew 
Wisteria
Yam bean - roots, immature roots

Harmful Plants (other sources)
Alacia
Apricot
Autumn Crocus/Meadow Saffron
Beans - all types if uncooked
Birch
Bittersweet Nightshade
Bleeding Heart/Dutchman's Breeches
Bloodroot 
Bracken Fern
Broomcorn Grass
Candelabra Tree
Cardinal Flower
Cherry Tree - bark, twigs, leaves, pits
Chinaberry Tree
Crown of Thorns
Croton
Elderberry
Euonymus/Spindle Tree
False Hellebore
Ficus (weeping)
Firethorn/Pyracantha
Four O'Clock
Glory Bean
Ground Cherry
Honey Locust
Honeysuckle
Horsetail
Indian Licorice Bean
Ivy
Jasmine
Jimsonweed/Thornapple
Jerusalem Cherry - berries
Johnson Grass
Kentucky Coffee Tree
Lupines/Bluebonnet
Mandrake
Mango Tree - wood,leaves,rind-fruit safe
Moonseed
Mountain Laurel
Mushrooms - several varieties
Nectarine
Nettles
Nutmeg
Oak - acorns, foliage
Peach
Peanuts - raw
Pencil Tree
Periwinkle
Pigweed
Pikeweed
Pine needles - berries 
Plum
Pothos
Prune
Rain Tree
Ranunculus/Buttercup
Red Maple
Sandbox Tree
Scarlet Runner Beans
Snowflake 
Sorghum Grass
Sorrel
Sudan Grass
Tansy Ragwort
Vetch
Yello Jasmine
Yew (Amer,Engl,Japan) - needles, thistles

 
Taken from Birds n Ways http://www.birdsnways.com/articles/plntstox.htm
 
Sources: American Medical Association Handbook of Poisonous and Injurious Plants ; R. Dean Axelson, Caring for Your Pet Bird; Gallerstein, Gary A., DVM, The Complete Bird Owner's Handbook; Garry Gallerstein, Bird Owner's Home Health and Care Handbook; Greg and Linda Harrison, eds, Clinical Avian Medicine and Surgery; Gillian Willis; Wade and Carol Olyer Parrot Pleasures, Safe Wood Products and more