Asteraceae, the daisy, sunflower or composite family.
Description:
Plant:
Course, usually much branched plant 1'-5', often hairy, with dissected leaves
and many erect, elongated clusters of small green flowers. Annual.
Flowers:
Green, tiny, with no apparent petals.
Two types. Male (staminate) flowers in long spike-like clusters up to 6" long, Typically many per plant. Individual florets resemble downturned cups
on short stems containing bunches of stamens.
Female (pistillate) flowers are inconspicuous, and occur singly or in small
groups in the leaf axils.
Leaves:
Usually alternate, highly dissected, pinnately or bipinnately lobed,
to 4" long.
Fruit:
Small, seedlike.
Blooming:
August-October
Habitat:
Waste areas, fields, roadsides.
Comments:
Ragweed is highly variable in appearance, with several
recognized varieties.
A common weed, the plant is wind-pollinated, consistent with the
inconspicuous flowers. The pollen is a primary cause of hay fever.
Given this, the genus name (ambrosia, nectar of the gods) seems a bit
incongruous.
The seeds are an important winter food source for some birds.
Where to find it:
Mostly along the roads and lawn boundaries.