The term 'spiny plant' can refer to a variety of plants, including CACTUS (6 letters), THORN (5 letters), aloe (4 letters), AGAVE (5 letters), and NETTLE (6 letters). Cacti are succulent plants that are typically found in dry, desert climates and have spines or thorns on their stems. Thorns are sharp, pointed structures that grow on the stems of some plants for protection. Aloe is a genus of succulent plants that have thick, fleshy leaves and spines along the edges. AGAVE is a genus of succulent plants that are native to the Americas and have spines along their leaves. Nettles are herbaceous plants that have stinging hairs on their stems and leaves.