Aquatic, Wetland and Invasive Plant Glossary
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Click one of the letters above to be taken to a page of all terms beginning with that letter.
- palea search for term
- - n. (L. palea, chaff) the upper, and usually shorter and thinner, of two membranous bracts enclosing the flower in grasses.
- palmate search for term
- - a. (L. palma, palm) leaves divided into lobes arising from a common center.
- pandurate search for term
- - a. (L. pandura, a bandore) shaped somewhat like a violin, as some leaves.
- panicle search for term
- - n. (L. panicula, a tuft of plants) a branched racemose inflorescence often applied more widely to any branched inflorescence.
- paniculate search for term
- - a., panicled; arranged or growing in panicles.
- papilla search for term
- - n. (L. papilla, nipple) a glandular hair with one secreting cell above the epidermis level.
- papillose search for term
- - a. (L. papilla, nipple) descriptive of a surface beset with short, blunt, rounded, or cylindric projections.
- parenchyma search for term
- - n. (Gr. para, besides; enchyma, infusion) plant tissue, generally soft and of thin-walled, relatively undifferentiated cells which may vary in structure and function.
- parietal search for term
- - a. (L. paries, wall) when the placenta is attached to the wall of the ovary.
- peat search for term
- - n. (ME. pete, fr. ML. peta, perh. of Celt. origin; akin to W. peth, thing - more at piece) a piece of turf cut for use as a fuel; a mass of partially carbonized plant tissue formed by partial decomposition in water of various plants and esp. of mosses of the genus Sphagnum, widely found in many parts of the world, varying in consistency from a turf to a slime used as a fertilizer, as stable litter, as a fuel, and for making charcoal.
- pectinate search for term
- - a. (L. pecten, comb) comb-like.
- pedicel search for term
- - n. (L. pedicellus, foot) the stalk of a flower in an inflorescence.
- peduncle search for term
- - n. (LL. pedunculus, small foot) the stalk of a flower borne singly or the stalk of an inflorescence.
- peltate search for term
- - a. (Gr. pelta, target) shield-shaped, leaves that are shaped like a shield and attached to the stem at the center or by some point distinctly within the margin, and having the petiole inserted into the undersurface of the lamina not far from the center.
- penicullate search for term
- - a. (L. penicillus, a pencil or small brush) having the form of a pencil.
- perennation search for term
- - n. (L. perennis, perennial) survival of a plant for a number of years. To live over from season to season.
- perennial search for term
- - a. (L. perennis, through; annus, a year) a plant that grows for 3 or more years and usually flowers each year.
- perfect flower search for term
- - a flower with both essential and accessory organs.
- perfoliate search for term
- - a. (L. per, through; folium, a leaf) said of opposite or whorled leaves or bracts that are united into a collarlike structure around the stem that bears them.
- perianth search for term
- - n. (Gr. peri, around; anthos, flower) the outer whorl of floral leaves of a flower, when not clearly divided into calyx and corolla; collectively, the calyx and corolla, or either one if one is absent.
- pericarp search for term
- - n. (Gr. peri, around; karpos, fruit) the fruit wall which has developed from the ovary wall; sometimes used for any fruit covering.
- perigynium search for term
- - n. (Gr. peri, around; gyne, female) fruit investing utricle of the sedges, Carex.
- perigynous search for term
- - a. (Gr. peri, around; gyne, female) growing in a ring around the pistil, as the stamens; having stamens, etc. growing in this way, said of a flower.
- persistent search for term
- - a. (L. persistere, to persist) remaining attached after the normal function has been completed.
- petal search for term
- - n. (Gr. petalon, leaf) any of the component parts, or leaves, of a corolla; the unit of structure of the corolla.
- petaloid search for term
- - a. (Gr. petalon, leaf; eidos, form) like a petal.
- petiolate search for term
- - a. (L. petiolus, small foot) growing on, or provided with, a petiole.
- petiole search for term
- - a. (L. petiolus, small foot) the slender stalk or stem of a leaf, also called a leaf stalk.
- phenotype search for term
- - n. (Gr. phainein, to appear; typos, image) the characters of an organism due to the interaction of genotype and environment, a group of individuals exhibiting the same phenotypic characters. The detectable expression of the interaction of genotype and environment constituting the visible characters of an organism.
- phenotypic search for term
- - a., a set of characters arising from reaction to environmental stimulus.
- phloem search for term
- - n. (Gr. phloios, inner bark) the tissue involved in the transport of carbohydrates and food materials in a vascular plant, being composed of sieve elements, parenchyma cells and sometimes also of fibers and sclereids.
- phyllode search for term
- - n. (Gr. phyllon, leaf; eidos, form) a winged petiole with flattened surfaces placed laterally to the stem and functioning as a leaf.
- phyllotaxy search for term
- - n. (L. phyllo-, and Gr. taxis, arrangement) the arrangement of the leaves on the stem. The three common positions are alternate, opposite, and verticillate.
- phylogeny search for term
- - n. (Gr. phyle, tribe; E. genesis) the racial history or evolutionary development of any plant or animal species.
- pileus search for term
- - n. (L. pileus, cap) umbrella-shaped structure of mushrooms or toadstools.
- pilose search for term
- - a. (L. pilosus, hairy) hairy; pubescence comprised of scattered long, slender, soft hairs.
- pinna search for term
- - n. (L. pinna, feather) a leaflet or a primary division of a compound leaf. pl. pinnas or pinnae.
- pinnate search for term
- - a. (L. pinnatus, feathered) divided in a feathery manner; with lateral processes of a compound leaf, having leaflets on each side of an axis or midrib.
- pinnule (also pinule) search for term
- - n. (NL. pinnula, fr. L., small feather, small fin) a secondary pinna, one of the ultimate divisions of a bipinnate or twice-pinnate leaf.
- pistil search for term
- - n. (L. pistillum, pestle) the unit of female function of a flower, may be comprised of a single carpel or two or more carpels united.
- pistillate search for term
- - n., said of a flower bearing a pistil or pistils but not stamens, may refer also to a plant having only pistillate flowers.
- pith search for term
- - n. (AS. pitha, pith) the soft, spongy tissue, consisting of cellular tissue, in the center of certain plant stems.
- placenta search for term
- - a. (L. placenta, flat cake) the part of the ovary from which the ovules arise. It generally occupies the whole or a portion of an angle of a cell.
- placentation search for term
- - n., the manner in which the placenta is arranged in the ovary.
- plano-convex search for term
- - flat on one side and convex on the other.
- plant search for term
- - n. (L. planta, plant) any of a kingdom (Plantae) of living beings typically lacking locomotive movement or obvious sensory organs, generally making its own food, possessing cell walls, and unlimited growth.
- plantlet search for term
- - n., a little plant.
- plicate search for term
- - a. (L. plicatus, to fold) folded into plaits, usually lengthwise; arranged in pleats, as a fan.
- plumose search for term
- - a. (L. plumosus, feather) with hairlike branches, feathery.
- pocosin search for term
- - n. (Algonquian) a bog that has formed in a shallow, undrained depression, the surrounding land being somewhat elevated, the vegetation predominantly evergreen shrubs or small trees. Pocosins vary greatly in size.
- pollen search for term
- - n. (L. pollen, pollis, fine flour) the male or fertilizing element of seed plants, consisting of fine yellowish powder formed within the anther of the stamen.
- pollinium search for term
- - n., a mass of coherent pollen characteristic of orchids and milkweeds.
- polygamo-dioecious search for term
- - polygamous but chiefly dioecious.
- polygamo-monoecious search for term
- - polygamous but chiefly monoecious.
- polygamous search for term
- - a. (Gr. polys, much or many; gamos, marriage) having bisexual, pistillate, and staminate flowers on the same individual plant.
- polymorphic search for term
- - a. (Gr. polys, many; morphe, shape) having, assuming, or occurring in various forms, characters, or styles.
- polypetalous search for term
- - a. (Gr. polys, many; petalon, a petal) with many separate petals.
- pond search for term
- - n. (form of pound, enclosure) a body of standing water smaller than a lake, often artifically formed.
- prickle search for term
- - n. (ME. prikle, prikel, fr. OE. prickle, pricel; a kin to MD. prikel, prickle) a sharp pointed emergence arising from the epidermis or bark of a plant.
- primary production search for term
- - the quantity of new organic matter created by photosynthesis.
- procumbent search for term
- - a. (L. pro, forward; cubare, to lie down) trailing or lying flat but not rooting.<
- production search for term
- - n. (L. producere, to produce) the weight of new organic material formed over a period of time, plus any losses during that time period. Losses may be due to respiration, excretion, secretion, injury, death, or grazing.
- productivity search for term
- - n., amount of production over a given period of time. Expressed as a rate such as g/m2 per day, kg/ha per year, etc.
- proliferous search for term
- - a. (L. proles, prolis, offspring; ferre, to bear) bearing supplementary structures such as buds or flowers, either in an abnormal manner or in a manner that is normal but from adventitious tissue.
- propagulum or propagule search for term
- - n. (L. propages, layer of a plant) a runner or sucker used in the asexual propagation of plants. pl. propagula or propagules.
- prostrate search for term
- - a. (L. prostratus, pp. of prosternere, to lay flat) growing on the ground, trailing.
- protogyny search for term
- - n. (Gr. proteros, fore; gyne, female) development of the female organs before the appearance of the corresponding male products - thus inhibiting self-fertilization.
- pseudolamina search for term
- - n. (Gr. pseudes, false; L. lamina, plate) the extended apical portion of a phyllode.
- pseudovivipary search for term
- - n. (Gr. pseudes, false; L. vivus, alive; parere, to produce) a condition where vegetative propagules replace some or all of the normal sexual flowers in the inflorescence.
- Pteridophyte search for term
- - n. (Gr. pteris, fern; phyton, plant) a major division of the plant kingdom, having clear alternation of generations with a dominant vascular sporophyte initially dependent upon the gametophyte which is very reduced.
- puberulent search for term
- - a. (L. pubes, adult) covered with fine, short, and nearly imperceptable down; minutely pubescent, the hairs soft, straight, erect, but scarcely visible to the unaided eye.
- pubescent search for term
- - a. (L. pubescere, to become mature) a general term for hairiness; covered with soft hair or down.
- punctate search for term
- - a. (L. puntcum, point) dotted; with depressed dots scattered over the surface.
- pustulate hair search for term
- - a. (L. pustulare, to blister) hair with an enlarged base.
- pyriform search for term
- - a. (L. pyrum or pirum, a pear) pear-shaped.