cuman ragweed (Ambrosia psilostachya)
- This is part of Allergy Agents
- When to observe: Year-round
- What to observe: Flowers, Fruits, and Leaves
New growth of the plant is visible, either from above-ground buds with green tips, or new green or white shoots breaking through the soil surface. Growth is considered "initial" on each bud or shoot until the first leaf has fully unfolded.
In at least one location on the plant, a fully unfolded leaf is visible. For seedlings, consider only true leaves and do not count the cotyledons (one or two small, round leaves) that are found on the stem almost immediately after the seedling emerges.
One or more fresh flowers or flower heads (inflorescences) are visible on the plant. Flower heads include many small flowers that usually do not open all at once. Do not include wilted or dried flowers that remain on the plant, or heads whose flowers have all wilted or dried.
One or more open fresh flowers are visible on the plant. Flowers are considered "open" when the reproductive parts (male stamens or female pistils) are visible between unfolded or open flower parts. Do not include wilted or dried flowers that remain on the plant.
One or more flowers on the plant release pollen when gently shaken or blown.
One or more fresh fruits are visible on the plant.
One or more ripe fruits are visible on the plant.
|Recent fruit drop
One or more fresh mature fruits or seeds have dropped or been removed from the plant since your last visit. Do not include obviously immature fruits that have dropped before ripening, such as in a heavy rain or wind.