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A spine is a rigid, pointed surface protuberance or needle-like structure on a plant, presumably serving as a defense against attack by predators. Examples include the spines of a hawthorn, the needles of a cactus, or the prickles of a shrub like the rose are all spines. Although spines generally serve as a passive defense mechanism, in some species they can be hollow and contain poisonous substances that cause lasting pain or even paralysis, and in others, may be barbed and detatch readily, sticking to whatever brushes against them.
Plant spines and thorns Botanists use several terms somewhat loosely when referring to spine- or needle-like structures on plants; however, the following differences are typically distinguished: Thorns and prickles, most notably those on roses, are common literary symbols for the hidden dangers or woes of something beautiful or pleasant, as in "Every rose has its thorn". Roses lack true thorns since their prickles emerge from the epidermis rather that the pericycle. Growth from the pericycle would make it a modified stem and therefore a thorn. Some roses have been bred not to have prickles. | ||||||||
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