Panicum amarum Elliott. Section: Hiantes. Bitter Seabeach Grass. Phen: Aug-Nov (-Jul). Hab: Coastal dunes and shores. Dist: RI and CT south to FL, west to se. and e. TX, south to the Caribbean coast of Mexico and Belize, restricted to the coast.

ID notes: Panicum amarulum and P. amarum are similar and sometimes confusable. They differ in general growth habit (long-rhizomatous with single stems in P. amarum vs. short-rhizomatous with dense multistem tufts in P. amarulum); foliage color (glaucous blue-green in P. amarum vs. green or yellowish green in P. amarulum); and panicle architecture (narrow, contracted, and spikelike in P. amarum vs. wider and more divergently many-branched in P. amarulum). Although the two sometimes co-occur in Coastal dune systems, P. amarulum is primarily a plant of secondary dunes and inland sands while P. amarum is most abundant on foredunes, upper beaches, and overwash flats (Virginia Botanical Associates 2023).

Origin/Endemic status: Native

Taxonomy Comments: See note under P. amarulum.

Synonymy ⓘ: = C, F, G, HC, RAB, S, Tat; = Panicum amarum Elliott ssp. amarum – FlGr, FNA25, NE, NY, Zuloaga & Aliscioni (2023); = Panicum amarum Elliott var. amarum – K1, K3, K4, Meso6, Pa, Va, Lelong (1986); < Panicum amarum Elliott – Mex, WH3

Show in key(s)

Show parent genus

Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: FAC (taxonomic split from wetland indicator species)
• Eastern Mountains and Piedmont: FACU (taxonomic split from wetland indicator species)
• Great Plains: FACU (taxonomic split from wetland indicator species)
• Northcentral & Northeast: FACU (taxonomic split from wetland indicator species)

Heliophily ⓘ: 9