Pineapple-weed (Matricaria discoidea) Photo: John D. Byrd, Mississippi State University, Bugwood.org
Pineappleweed (Matricaria matricarioides) reproduces from seeds. The first pair of leaves are opposite, bright green and have few lobes. The following leaves have an alternate arrangement and are divided into fine, linear lobes. Young plants form a rosette before mature growth begins. Mature plants have elongate stems that are smooth and grow laterally or vertically. They can reach a height of over 12 inches.
The leaves have a distinct odor that resembles pineapple. They are alternate and finely divided, which gives the plant a "soft" appearance. Flowers are produced throughout most of the growing season from April through September. The flower heads are rounded and greenish yellow. There are no petals. The flowers and leaves are edible and a tea can also be made from the flowers.
Pineappleweed grows in a variety of locations including turf areas, particularly poorly maintained locations, landscape beds, or nursery fields. It has a shallow taproot, but also a fibrous root system. If the root system isn't too extensive, plants can be had removed. This would be particularly beneficial before they set seeds.
Pre-emergence herbicides include:
- dithiopyr (Dimension)
- flumioxazin (Broadstar/SureGuard)
- napropamide (Devrinol)
Post-emergence herbicides that provide the best control are:
- clopyralid (Lontrel)
- flumioxazin (SureGuard)
- glyphosate (Roundup)