Scientific Family
Poaceae
Synonyms
Digitaria paspaloides, Paspalum distichum L. var. indutum, Paspalum paspaloides
Other common names
seashore paspalum
salt jointgrass
water finger-grass
Thompson grass
ginger grass
eternity grass
Plant type
Grasses
Riparian
Yes
Grass Description
Origin
Native
Season
Warm
Found in riparian areas in wet soils and sometimes floating in shallow water.
Plant Community
Riparian
Low elevation
3500
High elevation
6000
Similar species
P. dilitatum
General Description
This is a spreading, extensively stoloniferous perennial that forms dense, extensive mats. Erect stems are 7 to 20 inches long and sometimes covered with short soft hairs. Stolons.
Perennial; extensive stolons; sheaths hairy; blades smooth; seedheads 2, rarely 1 or 3; spikelets 3 mm long; glumes smooth or sparsely hairy; first glume absent or vestigial. P. dilatatum taller; less stoloniferous; very hairy spikelets.
Grass type
Perennial mat or sod-forming
Rhizomes
No
Stolons
Yes
Clump Diameter 2 ft or more
Yes
Bushy - highly branched
No
Height with Seedheads
12 inches or more
Seedhead Structure
Branched - fingerlike
Seedhead droops
No
First bloom month
June
Last bloom month
September
Flower Characteristics
Flowers per Spikelet
One-flowered
Spikelets One-Sided
Yes
Awns
Absent
Three Awns
No
Awns bent
No
Flower and Seedhead Notes
Seedhead is a pair of branches in a V shape. There is sometimes a third branch. Awnless spikelets are tightly appressed in 2 rows along the spike, often with purple stigmas sticking out. Spikelet has 2 florets, the lower sterile and the upper bisexual.
Vegetative Characteristics
Blade is hairy
Yes
Blade margins white
No
Blade cross-section
Flat
Involute – rolled inward on upper surface
Leaf blades are flat, 2 to 6 inches long, 1/8 to 1/4 inch wide, rolled upward on longitudinal edges. Blades may be smooth or sparsely hairy.
Sheath is hairy
Yes
Tufts of hair top of sheath or collar
Yes
Ligule
Membranous
Auricles
No
Knotgrass is grazed by many mammals and is a valuable food source for ducks.