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Prickles on a blackberry branch. In plant morphology, thorns, spines, and prickles, and in general spinose structures (sometimes called spinose teeth or spinose apical processes), are hard, rigid extensions or modifications of leaves, roots, stems, or buds with sharp, stiff ends, and generally serve the same function: physically defending plants against herbivory.
Viburnum lesquereuxii leaf with insect damage; Dakota Sandstone (Cretaceous) of Ellsworth County, Kansas. Scale bar is 10 mm. Knowledge of herbivory in geological time comes from three sources: fossilized plants, which may preserve evidence of defense (such as spines) or herbivory-related damage; the observation of plant debris in fossilised animal feces; and the structure of herbivore mouthparts.
Prickles and thorns are an evolved defense against herbivores — animals that eat plants — and can also aid in growth, plant competition and water retention, according to the study. It was ...
Besides their chemical content, the spiny leaves may also cause mechanical damage to the body. Iris sibirica: Siberian iris, Siberian flag Iridaceae: Most parts of the plant are poisonous (rhizome and leaves), if mistakenly ingested can cause stomach pains and vomiting. Also handling the plant may cause a skin irritation or an allergic reaction ...
The hooks or teeth generally cause irritation, and some species commonly cause gross injury to animals, or expensive damage to clothing or to vehicle tires. [citation needed] Burs serve the plants that bear them in two main ways. Firstly, burs are spinescent and tend to repel some herbivores, much as other spines and prickles do. [3]
Dry, one-seeded indehiscent fruit [11] in which the true fruit is not the so-called "berry", but the achenes, which are the so-called "seeds" on the infructescence, e.g. in the genus Fragaria. acicular Slender or needle-shaped. [11] See also Leaf shape. acropetal Moving from roots to leaves, e.g. of molecular signals in plants. acrophyll
Most cacti possess spines, some large enough to cause serious wounds. Glochids however, though smaller, commonly induce more troublesome, more persistent, dermatological manifestations in humans. Though minute, glochids commonly are barbed and once they have penetrated the skin barbed glochids are practically impossible to dislodge without ...
The homology of leaves is an easy conclusion to make. The plant morphologist goes further, and discovers that the spines of cactus also share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well.