Cats can be allergic or toxic reactions to certain flowers and plants, with some being particularly harmful or even deadly. Common flowers that are toxic and can cause allergic reactions or poisoning in cats include lilies (extremely toxic, causing kidney damage), amaryllis, daffodils, tulips, chrysanthemums, hyacinths, gladioli, cyclamen, and foxglove. These plants can cause symptoms like vomiting, diarrhea, drooling, lethargy, tremors, seizures, and in severe cases, death. Cats may also be allergic to pollen from some flowers, leading to respiratory and skin issues like itching, excessive grooming, and hair loss. Flowers that are relatively safe for cats include roses, orchids, alstroemeria, asters, and sunflowers, though ingestion of any plant material may cause mild stomach upset. It is important to avoid bringing toxic flowers into homes where cats live and seek veterinary care immediately if ingestion is suspected. Thus, cats can be allergic or poisoned by flowers such as lilies, tulips, daffodils, chrysanthemums, and several others, so these should be avoided around cats for their safety. This summary is based on detailed information about which flowers are toxic and allergenic to cats from multiple trusted sources including veterinary advice and poison control guidelines.