Aster family (Asteraceae)
Description: This herbaceous plant is an annual that becomes 1-2' tall, branching occasionally to frequently. The stems are light green, purplish green, or purple with fine longitudinal veins; they are glabrous and terete (round in cross-section). The alternate leaves are up to 3" long and 1½" across; they are green to dark green and double- or triple-pinnate. The leaves occur rather sparingly along the stems; they are sessile or have short petioles. The leaf segments are linear-filiform and glabrous. Each upper stem usually terminates in 1 or 2 daisy-like flowerheads. Each flowerhead spans about 1-2" across; it consists of 10-20 white ray florets that surround numerous yellow disk florets. The ray florets are oblong and petal-like; they spread outward or droop downward, depending on the maturity of the flowerhead. The tubular disk florets are arranged densely together on a receptacle that is globoid, subgloboid, or conical: the shape of this receptacle depends on the maturity of the flowerhead. There are no chaffy scales on the receptacle and it is hollow inside. At the base of each flowerhead, there are 1-2 series of floral bracts; these bracts are light green, lanceolate, and membranous along their margins. Each flowerhead has a naked peduncle (or flower stalk) at its base of varying length. The crushed flowerheads have a fruity fragrance, resembling pineapple or apple; sometimes the crushed leaves are fragrant as well. The blooming period usually occurs during the summer and lasts 1-2 months; some plants may bloom a little earlier or later than this, however. Each disk or ray floret is replaced by a small oblongoid achene. Each achene is nearly terete and has several fine ribs. The root system is mostly fibrous. This plant spreads by reseeding itself.
Cultivation: Naturalized plants are typically found in open areas that are sunny and moist to slightly dry, where the soil consists of loam or clay-loam. Other soil types are probably tolerated as well.
Range & Habitat: German Chamomile naturalizes occasionally in southern and west-central Illinois, while it is uncommon or absent elsewhere (see Distribution Map). It was introduced from Europe into North America as an ornamental plant and garden herb. In Illinois, typical habitats for this species include disturbed meadows, vacant lots, areas along roads and railroads, and waste areas. German Chamomile is still grown in flower and herbal gardens, from which it occasionally escapes. Usually, populations of these escaped plants don't persist for very long. Disturbed open areas are preferred.
Faunal Associations: The nectar and pollen of the flowerheads attract small bees and various flies primarily. Less common visitors of the flowerheads include small butterflies, wasps, beetles, and plant bugs.
Photographic Location: Along a barren roadside in Urbana, Illinois. The leaf of the lower photograph may have some mildew.
Comments: Several species of plants with white daisy-like flowers have been introduced from Europe; the classic example is Leucanthemum vulgare (Ox-Eye Daisy). They are often difficult to distinguish from each other. German Chamomile (Matricaria chamomilla) can be distinguished from other species in this group by its fragrant crushed flowerheads, which are hollow on the inside, and by its linear-filiform leaves. Similar species have flowerheads that lack a pleasant fragrance, or their flowerheads are solid inside; many of these species have leaves that are flat and narrow, rather than terete and worm-like (filiform). The flowerheads of German Chamomile often have receptacles that are more conical or ovoid in shape than those of other species in this group (which tend to have flatter receptacles). However, the shape of its receptacles varies significantly with the maturity of the flowerheads. Other common names that are sometimes applied to this wildflower are Wild Chamomile, False Chamomile, and Scented Mayweed. A scientific synonym for this species is Matricaria recutita.