Asteraceae: Symphyotrichum lanceolatum
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Family Name
Asteraceae
Common Name
White panicle aster, Lance-leaved aster
Description
Symphyotrichum lanceolatum is a perennial, herbaceous plant with a fibrous root system and long, creeping rhizomes, frequently forming dense colonies. Mature plants typically reach 60–150 cm in height. Stems are erect, slender, often branching in the upper half, and smooth or slightly roughened, sometimes with sparse, fine hairs. Leaves are alternate, simple, and lanceolate to narrowly elliptic, 5–20 cm long and 0.5–3 cm wide, with entire or finely toothed margins and pointed tips. Basal leaves may have short petioles and are often withered by flowering time; stem leaves are sessile, often clasping the stem with a heart-shaped or auriculate base. Leaf surfaces are medium to dark green, smooth or slightly rough above, and glabrous or slightly hairy below. Stipules are absent. Flowering occurs from August to October, with inflorescences forming large, spreading, and branched panicles up to 30 cm long, each with many daisy-like flower heads. Each involucre is cylindric, 4–6 mm long, with 3-6 rows of overlapping, green, lanceolate phyllaries with translucent margins, the outer layer shorter than the inner. Each head contains 12–25 white (occasionally pale blue or pink) ray florets (petals), each 5–9 mm long and about 1 mm wide, and 8–20 yellow disc florets. Stamens are five per disc floret, with yellow anthers about 1 mm long, forming a tube around the style. The pistil consists of a single compound ovary per floret, with a slender style about 2 mm long and a bifid (two-parted) stigma. The fruit is a small, dry, ribbed cypsela (achene), 2–2.5 mm long, brown when mature in fall (October to November); each is topped with a white, hair-like pappus 3–5 mm long for wind dispersal. White panicle aster is native to South Dakota and is found statewide in moist prairies, meadows, stream banks, ditches, and open woods, typically in moist to moderately moist, well-drained soils under full sun to partial shade.
Synonym: Aster lanceolatus
Horticulture Notes
Seed collection: Collect seeds from heads from October to November when achenes are fully mature and readily detach.
Germination: Seeds require light for germination; sow on the soil surface. Cold, moist stratification (30–60 days) may enhance germination rates.
Vegetative propagation methods: Propagated readily by division of rhizomes or basal clumps in spring or fall.
Soils: Prefers moist, well-drained soils but tolerates a wide range, including clay and sandy loams.
Light: Thrives in full sun to partial shade.
Water: Prefers moderate to moist soils; tolerates periodic flooding but not prolonged drought.
Additional Notes
Lance-leaved aster supports pollinators like bees and butterflies, providing late-season nectar and pollen. It is used in wetland restoration, naturalized landscapes, and native gardens for its attractive flowers and ability to thrive in moist soils. The plant also offers shelter and seeds for wildlife. It tolerates a range of soil moisture conditions but prefers moist sites.