I am a plant with a unique adaptation to survive in arid environments. My leaves are reduced to spines, and my stems are thick and green, acting as my primary photosynthetic organs. I am also known for my vibrant, showy flowers that bloom in a variety of colors. What am I?

1. I am often found in desert regions.
2. My spines help protect me from herbivores and reduce water loss.
3. My flowers are a source of nectar for pollinators.
4. I belong to the Cactaceae family.