Appendix C. Glossary

calibration species — A set of 20 plants selected to help “calibrate” phenological measurements across the USA. These native and introduced plants have broad distributions and are ecologically or economically significant. Observations on calibration species will be integrated to get “the big picture” regarding plant response to environmental change. Widespread observation of calibration species helps integrate collective plant data with climate change measurements nationwide.

canopy — A layer of vegetation elevated above the ground. It can refer to the layer of vegetation that comprises the top layer of a forest or the layer of leaves surrounding an individual tree or shrub

canopy composition — The tree species that comprise a forest canopy

caterpillar — Larval form of butterflies and moths

cotyledon — seed leaf; embryonic leaf; the first leaf or one of the first pair of leaves to develop in a seed plant. Cotyledons, when they emerge with seedling shoot, do not look the same as the plant’s “true leaves,” which develop after germination.

deciduous — Falling off, as leaves from a tree; not evergreen; not persistent

forb — Herbaceous (non-woody) flowering plants that are not grasses, sedges or rushes.

forest stature — The stage of growth of a forest or woodland; e.g., old growth (primary) and second or third growth (regrowth after disturbance/cutting)

habitat — The type of environment in which an organism usually resides (e.g., “marine habitat” or “woodland habitat”); an organism’s “address”

inflorescence — A group or cluster of individual flowers arranged on a stem that is composed of a main branch or an arrangement of branches. Milkweed flowers are arranged in an inflorescence.

larva — The newly hatched, earliest stage of any of various animals that undergo metamorphosis, differing markedly in form and appearance from the adult. Caterpillars are the larval form or larvae (pl) of butterflies and moths.

negative data — The record of not seeing an animal of study or observing that a phenophase is not occurring. Negative data is just as important as sightings of animals observing phenophase occurrence.

petiole — leaf stem; The petiole attaches a leaf or arrangement of leaflets to the main stem or branch of a plant

phenology — The recurring plant and animal life cycle stages or the study of these recurring plant and animal life cycle stages, especially their timing and relationships with weather and climate

phenophase — An observable stage or phase in the annual life cycle of a plant or animal that can be defined by a start and end point. A phenophase generally has a duration of a few days or weeks.

Examples include the period over which newly emerging leaves are visible or the period over which open flowers are present on a plant.

pistil — The female reproductive part of a flower made up of the ovary, style (stalk) and stigma (sticky tip that receives pollen).

pollen — A mass of microspores in a seed plant, usually appearing as a fine dust. Pollen grains are transported (typically by wind, water, insects or animals) from a stamen to a pistil, where fertilization occurs.

seaweeds — although they have many plant-like features, are not true vascular plants; they are algae, part of the Kingdom Protista, which means that they are neither plants nor animals. Seaweeds are not grouped with the true plants because they lack roots, stems, leaves, enclosed reproductive structures like flowers and cones and a specialized vascular system (a conducting system for fluids and nutrients). They are able to take up fluids, nutrients, and gases directly from the water, in which they come in contact and do not need an internal conducting system. Like true plants, seaweeds are photosynthetic, converting energy from sunlight into materials needed for growth. Seaweeds have the green pigment chlorophyll within their cells, which absorbs the sunlight they need for photosynthesis.

stamen — The male reproductive part of a flower made up of a filament (stalk) and anthers (contain pollen).

transect — A fixed path in a given area along which one observes and records occurrences of plants or animals of study.