Pineappleweed (Chamomilla suaveolens)
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Pineappleweed is a very common summer or winter annual broadleaf plant. It is found throughout California, except in the Great Basin and deserts, to 7900 feet (2400 m). Pineappleweed inhabits agricultural land, turf, and other disturbed areas. When crushed, the leaves and flower heads smell similar to pineapple.
Crop fields, vineyards, orchards, nurseries, pastures, sand bars, riverbanks, roadsides, gardens, turf, landscaped areas, and other disturbed places.
Cotyledons (seed leaves) are bright green, narrow, thick and fleshy, pointed or rounded at the tip, hairless, and are about 1/12 to 1/2 of an inch (2–12 mm) long and 1/25 of an inch (1 mm) wide. The leaves of the first pair are opposite to one another on the stem, hairless, and their leaf edges range from smooth to deeply lobed. Subsequent leaves are alternate to one another along the stem, deeply lobed to deeply divided into narrow fingerlike lobes, and form a rosette.
Plants can grow to about 1-3/5 feet (0.5 m) tall but generally are found about 0.5-1 ft tall (15-30 cm). Leaves are alternate to one another along the stem. They are hairless, stalkless, and finely divided one to three times into linear segments. Pre-flowering plants look similar to mayweed chamomile, Anthemis cotula. However, the crushed leaves of pineappleweed give off a sweet scent similar to pineapple, whereas mayweed chamomile's odor is less pleasant. Also, pineappleweed leaves are less finely divided and do not appear to clasp the stem.
Flowering takes place from May through August. Flower heads are found at the ends of stems, are egg shaped, and are composed of densely packed, tiny, non-showy, yellowish green flowers. They do not have the white petalike ray flowers surrounding a yellow center (disc flowers) as found in the daisey-like mayweed chamomile flowers.
At maturity flower heads shatter releasing tiny, lance-shaped, yellow, brown, or gray fruit that range from 1/25 to 1/12 of an inch (1–2 mm) long. Each fruit contains one seed.
Reproduces by seed.
Related or similar plants
- Mayweed chamomile, Anthemis cotula
- Southern brassbuttons, Cotula australis
- Mexican brassbuttons, Cotula mexicana
- Lawn burweed, Soliva sessilis