There are many lists and resources listing toxic plants (and common household toxins etc.) and I have collected many resources ncluding the one from Poultryhelp which is a very good quick reference:
http://www.poultryhelp.com/toxicplants.html
...however please read this little article before you go further from Blake Hawley, DVM :
http://www.oldworldaviaries.com/text/miscellaneous/toxicoses.html
(excerpt):
"....A growing concern for birds that is not related to toxic foods or agents found in foods is the practice of feeding table scraps. A common belief is that if birds eat people food, they will receive a good diet. Unfortunately, this is generally not the case for the following reasons. People generally do not eat healthy. The incidence of heart disease, cancer, and obesity in Americans is certainly due in part to poor dietary habits. While many people begin feeding their birds nutritious foods, these good intentions often decay into fatty, salty, fast food items. Even people who provide a well balanced table diet to their birds cannot guarantee consumption of all the diet provided. As with almost any diet, what is placed in front of the bird is not necessarily what it consumes.
Further, if a bird consumes a food which is high in calories, it may not be able to eat enough food to be properly nourished. Birds, like all animals, eat to meet their energy requirements. A single food source, provided in sufficient quantity, may provide a bird with its daily energy requirement, while depriving it of its daily nutrient needs. An example of this principle is a cookie. A single cookie may contain as many as 200 calories, or roughly the entire daily caloric requirement for a macaw!
Another problem with table scraps or human foods involves bulk. Birds are very small animals. Giving a parrot half an apple is equivalent to a person being given a ten pound head of lettuce to eat. Many foods, fruits especially, are high fiber foods, which may fill up the crop, proventriculus and ventriculus and lead to satiety (the state of being full, not hungry). Again, foods which contain high fiber or are high bulk, may fill the bird but not provide adequate nutrients.
Given then, certain "nutritious" foods are not necessarily good for your bird. Foods must be provided in the appropriate amounts and must be balanced for energy in an overall dietary scheme. Some foods however, should be avoided in any quantities......
Another item of concern in birds in sodium chloride, or salt. Salt, however is required by birds as it is by all living animals. While minerals, such as sodium and chloride only constitute a small fraction of the body weight, they are critical for a variety of functions within the body including acid-base balance, maintaining body fluid balance and many general cellular functions. A deficiency of sodium can cause polyuria (excessive fluid excretion), weight loss, fatigue, and slow growth. Many otherwise healthy foods that people routinely eat are high in salt. Further, many crackers, snack items, chips, fast foods, and canned vegetables (unrinsed) if eaten in sufficient quantities may actually be toxic to birds.
Signs of a mild salt toxicity (5-10 times requirement) will result in polydipsia, or increased water consumption and subsequent polyuria, or increased fluid (urine) in the droppings. Because excess salt is excreted via the kidneys, a bird with mild to moderate kidney dysfunction may consume toxic doses of salt readily. Deprivation of water alone may lead to salt toxicity because the kidneys are not proficiently perfused or bathed by fluids to remove the sodium and chloride.
Even birds with good kidney function may develop signs of a toxicity if salt is consumed in large quantities. Besides polydipsia and polyuria, a toxic insult of salt may lead to kidney failure (with no urine produced), a subsequent build-up of body fluids (ascites), neurological signs2 and heart failure leading to death.....
The other cause of contaminated food is mycotoxin tainted food. Mycotoxins are chemicals produced by certain varieties of molds and fungi. Often, the mold or fungi is no longer visible when the toxins are ingested, so these toxicities too are difficult to spot, but food can be tested for the presence of mycotoxins. The most common mycotoxins affecting grains are aflatoxin, ochratoxin, vomitoxin, and T2 toxin. These toxins cause clinical signs that include anorexia (not eating), depression, sores in the mouth, toxic liver changes, kidney failure, and rapid death.
Mycotoxicoses are easily prevented by feeding only high quality, clean seeds and grains or better yet, an extruded or manufactured diet (which is much less likely to contain mycotoxins because of the cooking process and the lack of moisture). The most commonly implicated foods with mycotoxins are poor quality peanuts and peanut butter, breads, meats, cheese, and grains. If a food smells moldy or certainly if mold is seen, the food should be discarded and not fed. Seed products which contain bugs, such as grain beetles or meal moths, should not be fed (it is unlikely that the bug itself would harm a bird, they certainly consume them in the wild, but the damage the bug does to the seed hull makes it more likely to be less nutritious and increases the possibility of contamination). ...."
...that having been said here are some of my collected articles and resources on toxic plants:
http://dlhunicorn.conforums.com/index.cgi?board=toxicologydisease&action=display&num=1165263379
...and poisonings (from plants as well as other sources):
http://dlhunicorn.conforums.com/index.cgi?board=emergencies&action=display&num=1176711905