Botanical Words Alphabetical List - PH
pH: A numerical designation of the acidity and alkalinity in soil and other biological systems. A pH of 7.0 indicates neutrality; above 7.0 indicates alkalinity, and lower indicates acidity.
PHANEROGAM: A seed plant or flowering plant, such as a pine tree, poppy, or bamboo, as opposed to a cryptogam, or spore-bearing plant, such as a fern or mushroom.
PHENOLOGY: The branch of science that deals with the influence of climate on periodic biological phenomena, such as the flowering of plants.
PHENOTYPE: The outward form, characteristic and appearance of a plant, produced by the interaction of environmental and situational factors upon the traits dictated by the plant's genes.
PHEREMONE: A chemical released by insects that attracts members of the same species. Pheremones are usually sexual in nature and are used to lure insects for trapping, monitoring populations, or to disrupt mating.
PHEREMONE TRAP: Any of various containers baited with sexual scent, used to lure and entrap garden pests.
PHOSPHOROUS: An element used by plants to promote root and tuber growth, and the production of flowers and seeds. In a commercial fertilizer, its proportion is represented by the second of three numbers; 5-10-5 fertilizer contains twice as much phosphorous as potassium or nitrogen.
PHOTOPERIOD: The relative lengths of alternating periods of darkness and light affecting the growth and maturity of an organism, as flowering, or the dropping of leaves of deciduous plants.
PHOTOPERIODISM: The ability to respond to the lengths of alternating periods of light and darkness.
PHOTOSYNTHESIS: This is the chemical reaction by which carbon dioxide and water combine producing oxygen and the sugars that the plants need for growth. This is accomplished by light acting on light-sensitive pigments called chlorophylls.
PHOTOTAXIS: The orientation of a plant or plant parts with reference to the direction of the source of light.
PHYLLARY: One of the bracts forming the involucre of flowers of the Compositae.
PHYLLOCLADE: A flattened stem or branch that assumes the functions of foliage, as the broad, succulent stems of the Cactaceae (Cactus family).
PHYLLODE: An expanded leaf stalk, which functions as and resembles a leaf blade. E.g. asparagus.
PHYLLODY: The metamorphosis of a plant organ, such as the corolla of a flower, into a green leaf.
PHYLLOGENETIC: Concerned with or relating to the development of leaves.
PHYLLOMANIA: The production of leaves in unusual numbers or in unusual places.
PHYLLOME: A leaf or plant part that is genetically derived from a leaf.
PHYLLOMIC: Pertaining to or resembling a phyllome.
PHYLLOPHORE: The top of a palm stem.
PHYLLOTAXY: The distribution or arrangement of leaves on a stem; also, the genetically determined laws that govern such distribution.
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