yes it is
Sedum is not listed on Poisonous Plants for Rabbits (link below), but in gardening circles it's widely reputed that wild rabbits don't often eat it. So, it may not be toxic, but I don't think you should give any to your pet rabbit.
Lots of things are toxic to rabbits. See the related link below for a comprehensive list of plants and plant parts known to be dangerous to rabbits. Ultimately, it's safest and easiest to stick to what's recommended to give to rabbits to eat. See the related question below about diet for more details and links.
Apple seeds are toxic to rabbits and many animals. Apple seeds contain a cyanide compound -- this is what makes them poisonous.
It is not listed for doing so in the link below.
No, rabbits can't eat tulip bulbs; tulips are toxic for rabbits. See the related link and question below for more info.
No, rabbits should not eat citronella. Citronella is toxic to rabbits and can cause digestive issues, neurological problems, and even death if ingested. It is best to keep citronella and other plants or substances that are toxic to rabbits out of their reach.
No, all parts of the holly plant are toxic for rabbits. See the related link and question below for more info.
Rabbits can eat some leftovers like fruits and vegetables, but it's important to make sure they are safe and not toxic for rabbits. Foods like chocolate, caffeine, and sugary or salty items should never be fed to rabbits. Always research which foods are safe for rabbits before offering them any leftovers.
There are some flowers that bunnies can eat (like roses, violets, dandelions), but there are also many flowers that are toxic or just unhealthy for bunnies. See the related links and questions below for more information.
Adult rabbits should have a diet that consists mostly of unlimited hay and water. In addition to that, an owner may choose to feed pellets, vegetables, and treats. Rabbits should not be fed any dairy or toxic plants. Read more information in the related links.
Some fruits and vegetables are okay as a treat, but they shouldn't be a regular part of your rabbit's diet. Rabbits should mostly eat hay; they should also eat pellets and fresh leafy greens daily.Neither tomato nor avocado are good for rabbits.Tomato leaves, vines, and stems are toxic to rabbits. Tomato fruit is not toxic, but it isn't very healthy, either; it may not be dangerous as a treat, but there are better treats to choose from (like carrot, blueberry, papaya, or pineapple).Avocado contain persin, a compound known to be toxic to rabbits. Rabbits should not eat avocado, especially not the leaves or pit.See the related questions/links below for more details.