The Crotalaria plant is the most common cause of liver damage in chickens resulting in Ascites Syndrome (water belly) a deadly but treatable infection. If you are raising chickens you need to locate and remove these plants from your property. "In poultry, liver damage may be caused by aflatoxin or by toxins from plants such as Crotalaria. In broiler chickens, obstructive cholangiohepatitis (caused by Clostridium perfringens infection) is the most common cause of the liver damage, which results in ascites. In both meat-type ducks and breeders, amyloidosis of the liver may also cause ascites" (Professor Billy M. Hargis, DVM, PhD).

The crotalaria plant was commonly used as a fibre crop (the fibers can be used to make rope, paper, and cloth. It is also used as green manure (cover crops left in fields to rot and create mulch), and was even used as a forage plant (grown for livestock to graze on) but as it turns out this plant is extremely poisonous to birds and livestock (1).
Pyrrolizidine alkaloids found in Crotalaria plants are toxic to chickens and the seeds of these plants are extremely poisonous to poultry, large mammals, and other birds. Studies show pyrrolizidine alkaloids in honey are a threat to human health as well (1).
Pyrrolizidine alkaloids found in Crotalaria plants are toxic to chickens and the seeds of these plants are extremely poisonous to poultry, large mammals, and other birds. Studies show pyrrolizidine alkaloids in honey are a threat to human health as well (1).
References:
1. Crotalaria retusa. (Aug. 27, 2017). Wikipedia.https://en.wikipedia.org/wiki/Crotalaria_retusa
2. Billy M. Hargis, DVM, PHD, Professor and Director: Tyson Sustainable Poultry Health Chair, JKS Poultry Health Research Laboratory. University of Arkansas; Department of Poultry Science, University of Arkansas. Merck Vet Manual http://www.merckvetmanual.com/poultry/miscellaneous-conditions-of-poultry/ascites-syndrome-in-poultry).
1. Crotalaria retusa. (Aug. 27, 2017). Wikipedia.https://en.wikipedia.org/wiki/Crotalaria_retusa
2. Billy M. Hargis, DVM, PHD, Professor and Director: Tyson Sustainable Poultry Health Chair, JKS Poultry Health Research Laboratory. University of Arkansas; Department of Poultry Science, University of Arkansas. Merck Vet Manual http://www.merckvetmanual.com/poultry/miscellaneous-conditions-of-poultry/ascites-syndrome-in-poultry).