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Weed Identification

thin paspalum

Family

Poaceae

Scientific Name

Paspalum setaceum

Other Common Names:

bead grass
slender beadgrass
tufted bead-grass

Synonyms (former Scientific Names):

Paspalum setaceum Michx. var. supinum
Paspalum debile
Paspalum separatum
Paspalum pubescens
Paspalum longepedunculatum
Paspalum setaceum var. calvescens
Paspalum setaceum var. ciliatifolium
Paspalum setaceum var. rigidifolium
Paspalum setaceum var. villosissimum
Paspalum bushii
Paspalum rigidifolium
Paspalum setaceum var. longepedunculatum
Paspalum stramineum
Paspalum propinquum
Paspalum psammophilum
Paspalum supinum
Paspalum muehlenbergii
Paspalum setaceum var. muehlenbergii
Paspalum ciliatifolium
Paspalum setaceum var. stramineum
Paspalum setaceum var. psammophilum

Habit

Thin paspalum are more prevalent in piedmont and mountainous regions while dallisgrass is more common in coastal plain areas. Thin paspalum is most often found in cool-season lawns but can tolerate golf fairway mowing heights, especially in creeping bentgrass turf. Thin Paspalum are typically found growing on open grasslands and wooded sites in sandy textured soils.

Leaves

The leaves of Thin Paspalum are the plant's best identification characteristic. The leaf margins have evenly spaced hairs, especially on the lower part of the leaf. The hairs typically extend at least a third of the total leaf length. Dallisgrass and smooth crabgrass are both similar to thin paspalum but do not have these evenly spaced hairs on the leaf margin.

Identifying Characteristics

Thin paspalum has evenly spaced hairs along the edge of leaves. The hairs are sometimes only found at the base of the leaf but typically extend at least one third of the way up the leaf and some times extend almost to the leaf tip. Dallisgrass does not have these evenly spaced hairs along the margin. Thin paspalum has seedheads that are similar to dallisgrass but not has hairy. Thin paspalum seedheads always arise from the plant at a sharp angle while dallisgrass often will have both angular and erect seedheads.

Flower Seed Head

Thin paspalum has rounded seed set in a spike consisting of two rows of seed along a stem at the top of the flowering stalk. Like dallisgrass, thin paspalum seed are not evenly distributed along the flowering stalk but tend to be found only on one side of the stalk. In contrast, other grasses typically have seed that are distributed on both sides of the stalk. The seedhead of thin paspalum is similar to dallisgrass but dallisgrass plants often have seedheads that are erect but thin paspalum flowering stalks are always slanted, even when plants are not clipped.

Seed Fruit

Seeds are small, round and flattened on one side and occur in two rows along the inflorescence branch. Seed are about the size and shape of the spikelet, pale, and shiny. Seed are not as hairy as dallisgrass.

Where Found

Thin paspalum can be found in the southern United States up to the upper transition zone. In Virginia, it is more common from Richmond and West but can be found most anywhere in the state.

Leaf Hair on Upper Surface

hairs on basal half only

Leaf Arrangement

rolled in bud

Mature Leaf Width

less than 5 mm

Stem

flat or oval

Seedhead

panicle

Life Cycle

perennial

Auricle

not present

Ligule

membrane

Ligule Length

less than 1 mm

Plant Type

Grass