Yellow Starthistle Information
Glossary for the Yellow Starthistle Information
Web Page
These words are listed in the order in which they appear in the web page.
Introduction and Spread
Pappus - the modified calyx (bracts) of flowers in the sunflower family (Asteraceae), usually as capillary bristles, feather-like bristles, scales, awns or a low crown.
Impacts
no glossary words
Biology and Ecology
Morphological - the structure or form of an organism.
Genotypic - the genetic constitution of an individual.
Allozyme electrophoretic - a technique that separates one or several forms of a particular enzyme on a gel. Separation is based on electrical charge and molecular weight of the enzymes. Allows for comparison of similarities or differences in selected protein patterns between organisms or populations of one species.
Interpopulaton - between populations. In this sense comparing divergence between separate populations. By comparison intrapopulation is within the same population.
Phenological - the physical traits or appearance of an individual.
Tetrazolium - dye used to stain seed embryo. If embryo stains red to purple the embryo is respiring and is considered living (viable).
Viable - living and capable of germinating under the right environmental and physiological conditions. Includes seeds that are immediately germinable or dormant.
Innate - inborn, natural, dependent on hereditary factors. For example, seeds may not germinate because embryos are immature or natural chemical inhibitors are present.
Induced - to bring about, to cause to occur. In seed dormancy, this term is often used to describe seeds that contain very hard seed coats that resist penetration of water and oxygen, and thus are unable to germinate even when environmental conditions conducive to germination are present.
Secondary dormancy - dormancy that develops after seeds have been dispersed from plants. Often refers to seeds that transition from a stage where they are germinable to a dormant stage.
Water potential - a measure of the moisture stress in plants or soil. A more negative value, measured in mega Pascals (mPa), indicates greater moisture stress. Soils with no moisture stress will have a water potential of 0 to -1 mPa.
Transpiration - the loss of water vapor from the surface of an organism. In plants, this refers to the loss of water from the leaves through the stomates.
Phyllaries - bracts associated with the outside of a flowerhead in members of the sunflower family (Asteraceae). For example, the edible bracts on the outside of an artichoke head.
Receptacle - the expanded flat, concave or conical portions of a flower or flowerhead in which the flowers and seeds are attached.
Chaff - reduced thin, dry bracts that are attached to the receptable adjacent to flowers in members of the sunflower family (Asteraceae). In yellow starthistle, these are the structures that give the senesced seedheads a cottony or Q-tip appearance in late fall and winter.
Photoperiod - the response in a plant or organism with changes in light intensity or daylength. In plants, photoperiod changes can lead to growth and development of flowers and fruit, the shedding of leaves, or onset of winter dormancy.
Vernalization - the induction of flowering by subjecting plants to low temperatures.
Management
Pathogen - a disease-causing organism
Virulence - highly infectious to the target organism
Mycoherbicide - a plant pathogen applied like a herbicide to control a specific weed.
Rope wick applicator - undiluted or diluted herbicide concentrate filled in a sealed container with end attachment consisting of felt, carpet, sponge or material that allows direct wiping of chemical onto plant surfaces.
Developing a Strategic Plan
Niche - a place or position occupied by or a type of organism. An activity engaged in by an organism relative to other organisms.
Weed Management Areas
no glossary words
