Symphyotrichum lentum (formerly Aster lentus) is a species of flowering plant in the family Asteraceae with the common name of Suisun Marsh aster. It is a perennial and herbaceous plant endemic to the marshes of Sacramento-San Joaquin River Delta of Northern California.
Symphyotrichum lentum is similar in appearance to Symphyotrichum chilense, which may be found in the same area. It is a colonial perennial herb producing a hairless stem tall from a long rhizome. The leaves are linear or lance-shaped, pointed, and up to long near the base of the plant. The lower leaves wither by the time the plant flowers. The inflorescence is an open array of flower heads with a fringe of violet ray florets around a center of yellow disc florets. The fruit is a hairy cypsela with a long white pappus.
Symphyotrichum lentum is endemic to the salt marshes and wet grasslands of the SacramentoâÂÂSan Joaquin River Delta in Northern California.
NatureServe lists it as Imperiled (G2) worldwide.