Symphyotrichum subulatum is an annual herb 10-100 cm tall, rather fleshy, from a taproot.
Leaves alternate, linear, entire, to 20 cm long, 1 cm wide.
Flowers greenish, tubular, of two types; rays short, inconspicuous, pale blue, numerous, disk flowers 5-15, yellow; in narrow heads with basal bracts (involucre) 0.5-0.8 cm tall, bracts overlapping, narrow, usually green with purple tips; inflorescence branched, heads solitary or few along a branch.
Fruit dry, 1-seeded, white-plumed achenes.
Wetland status: OBL.
Frequency in NYC: Infrequent.
Habitat: Salt marshes and brackish, open areas.