Vascular Plants of North Carolina
Account for Seashore Crowngrass - Paspalum vaginatum   Swartz
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Members of Paspalum with account distribution info or public map:
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Section 5 » Order Cyperales » Family Poaceae
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AuthorSwartz
DistributionOuter Coastal Plain and Outer Banks/barrier islands. Ranges north to Tyrrell and Dare counties. A specimen reportedly at USDA website is not supported by a collection at SERNEC.

Coastal Plain, NC to southern FL and southern TX; Neotropics.
AbundanceRare to uncommon. The NCNHP database contains 12 records, all extant. This is a Significantly Rare species.
HabitatMargins of brackish marshes, interdune marshes, maritime wet grasslands.
PhenologyFlowering and fruiting June-September.
IdentificationThis species is one of the few perennial crowngrasses in NC whose stems are often lazy and lie close to the ground. Lower stem nodes may take root. The inflorescence is composed of a single pair of branches. P. distichum may also grow similarly, but its leaves are spirally arranged versus 2-ranked (when viewed from above) in P. vaginatum, and it has shorter spikelets (2.5-3 mm long vs. 3-4 mm long in P. vaginatum).
Taxonomic CommentsNone

Paspalum is a genus of more than 300 species, found mostly in the New World. The genus is quite easily identified by the neat row of spikelets along each side of a flattened rachis (inflorescence branch), and also by the hemispherical outline of each spikelet. In some species there are only 2 such inflorescence branches, paired at the stem summit; in most of our species there are 3-4 branches; and in a few there may be many. Keys ask whether spikelets are paired or not -- that is, at each node on each side of the rachis there are pairs of spikelets on tiny stalklets. Care must be taken with a hand lens to make sure there are 2 stalklets at each node, as frequently one of the two spikelets will not grow. Non-paired or single spikelets will clearly have only a single stalklet per node.
Other Common Name(s)Seashore Paspalum is usually used, but the website editors prefer not using genus names in a common name, if a more descriptive group name (i.e., Crowngrass) is available. A few other common names are listed in Wikipedia, seldom in usage.
State RankS2
Global RankG5
State StatusSR-P
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