Pineapple Weed (Matricaria discoidea)
Pineapple weed is an annual plant from the Asteraceae family. This plant grows well in distressed areas and compacted, poor soils along walking paths, roadsides, riverbanks, gardens, turf areas, crop fields, pastures and more. It can grow up to 16 inches tall, but generally stay around 12 inches. It has several egg-shaped flower heads that are found at the ends of stems. The leaves are alternating and are hairless and if you crush the leaves or flowers, they will have a faint scent of pineapple. The flower heads are yellow to yellow-green color and contain 1 seed by which the pineapple weed reproduces.
Pineapple weed can begin blooming in the early spring to early summer and the flowers grow well from May to September.
Healthy, dense lawns will help to keep the seed from germinating.
Pineapple weed is a hardy plant that can be difficult to get rid of. If you have a healthy dense lawn, that should help, but you can also use a preemergent herbicide in the spring to prevent the seed from germinating or apply a postemergent herbicide when the weed is in full growth.