Asteraceae: Erigeron philadelphicus
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Family Name
Asteraceae
Common Name
Philadelphia fleabane
Description
Erigeron philadelphicus is a perennial herb that typically grows 30–90 cm tall with erect, slender stems that may be branched or unbranched and are covered with fine hairs (pubescent). The plant has a fibrous root system and may spread by short rhizomes. Leaves are alternate and simple, ranging from lanceolate to ovate, 5–15 cm long, with coarsely smooth to toothed margins and a rough texture. Both basal and cauline leaves are present, basal leaves forming a rosette early in the season and often dwindling by flowering time. Basal and lower leaves have petioles, while upper leaves may clasp the stem. Flowering occurs from late spring to early fall (May–September). Inflorescences are composed of multiple small, daisy-like flower heads arranged in loose clusters or panicles. Each flower head is about 1–2 cm across and contains 40–70 narrow white to pale pink ray florets surrounding numerous bright yellow disc florets. The ligule phyllaries are arranged in 2–3 overlapping series, broadly lanceolate to ovate, about 7–12 mm long, with pointed tips and a slightly hairy texture. The ray flowers are strap-shaped, about 7–12 mm long and 1.5–3 mm wide, mostly sterile or female, serving to attract pollinators. The disc flowers are tubular, perfect (bisexual), 2.5 to 4 millimeters in length. The corolla tube of each disc floret has five distinct lobes that spread slightly as the flower matures, forming a small, open star-shaped mouth, with five stamens fused by their anthers into a tube around the style. The style extends through the anther tube, its tip divides into two slender, slightly hairy stigmatic branches. The fruit is a small achene with a fluffy pappus allowing wind dispersal, maturing in late summer. Philadelphia fleabane is native to South Dakota and common in open woods, meadows, roadsides, and disturbed sites statewide.
Horticulture Notes
Seed Collection: Seeds mature when flower heads dry and pappi expand, typically late summer.
Germination: Seeds germinate readily without dormancy; sow in spring or fall on well-drained soils.
Vegetative Propagation: Not propagated vegetatively; reproduction is by seed.
Soils: Prefers moist, well-drained soils but tolerates a variety of soil types.
Light: Full sun to partial shade.
Water: Requires moderate moisture; tolerates short dry spells.
Additional Notes
Philadelphia Fleabane is valued for its ecological role in supporting pollinators such as bees and butterflies. The plant is not commonly cultivated but can be used in native plant gardens for its attractive flowers.