Panic-grasses

Bitter Panic-grass Bitter Panic-grass Switch-grass Diffuse Crab-grass

What are they?

Generally rather tall grasses with open, often graceful flower heads (though there are some smaller species). The genus was once much larger, but many species were moved to another genus, Dichanthelium and these species are treated in another page.

Where are they found?

Mostly found in open, sunny locations in fields and other grassy places; often in damper ground.

Identification

Panic-grasses are difficult to identify as a group due to their variability, but they are usually clump-forming species with large, rather showy flower heads. For species recognition, see the individual species comments.



Wood Panic-grass      Panicum philadelphicum

A low-growing species of wooded, shady areas, often found along tracksides. Flowers August to October. The combination of typical panic-grass florets, and richly hairy leaves and leaf sheaths is distinctive.
Wood Panic-grass Wood Panic-grass Wood Panic-grass Wood Panic-grass
Flower spike
Flower close-up
Leaf sheaths
Leaf ligule

Spreading Panic-grass      Panicum dichotomiflorum

(Fall Panic-grass) A common species in wetlands where it has a rather sprawling growth-style. Also sometimes found as a weed of waste places. Flowers August to October.
Spreading Panic-grass Spreading Panic-grass Spreading Panic-grass Spreading Panic-grass
Habit
Flower spike
Flower close-up
Leaf ligule

Bitter Panic-grass      Panicum amarum var. amarulum

(Seabeach Grass) Sandy coastal habitats, both wet and dry. Flowers August to October. A readily recognized grass due to its tall height (up to 2.5m), clump-forming habit and often rich bluish coloration. Even more showy when in flower due to its bright orange anthers. A common grass around Cape May Point where it has been widely planted on dunes. See below for the lower-growing, variety amarum.
Bitter Panic-grass Bitter Panic-grass Bitter Panic-grass Bitter Panic-grass
Habit
Flower spikes
Flower close-up
Leaf ligule

Bitter Panic-grass      Panicum amarum var. amarum

(Seabeach Grass) Sandy coastal habitats, especially upper beaches and dunes. Flowers August to October. This is the shorter variety (typically much less than 1m) of Bitter Panic-grass which tends to be bluer in color and forms low, spreading patches in less disturbed primary dunes, wherever a natural landscape is allowed to develop. Flowers are like those of the variety amarulum (above) but average a little smaller in overall size and have more (7-9 not 3-5) ribs on the glumes (the outermost part of the flower).
Bitter Panic-grass Bitter Panic-grass
Habit
Leaves

Switch-grass      Panicum virgatum

A common and widespread species, found in all manner of habitats; sometimes planted. Flowers July to September. The large, twiggy flowerheads or 'switches' are distinctive once known. A tall, rather lush-leaved species that often forms quite large stands.
Switch-grass Switch-grass Switch-grass Switch-grass
Habit
Flower spikes
Flower close-up
Leaf ligule

Maidencane Panic-grass      Panicum hemitomon

Swampy ground in wet hollows and edges of marshy areas. A rare species in Cape May, on the northern edge of its range. Flowers June to August. In our area, rarely flowers but often forms extensive, pure stands and then may resemble a short (knee-high), bright green stand of Common Reed.
Maidencane Panic-grass Maidencane Panic-grass Maidencane Panic-grass Maidencane Panic-grass
Habit
Seed head
Leafy stem
Leaf ligule

Warty Panic-grass      Panicum verrucosum

Common in boggy, often shady places in all kinds of swampy ground. Flowers July to September. A bright green species with small florets that are carried in small clusters at the ends of long side arms. With a hand lens, the outside of the florets will be seen to have warty bumps.
Warty Panic-grass Warty Panic-grass Warty Panic-grass Warty Panic-grass
Habit
Flower spike
Florets close-up
Leaf ligule

Red-top Panic-grass      Coleataenia rigidula

A grass of well-vegetated, swamy areas, especially along powerline cuts. Flowers July to September.
Red-top Panic-grass Red-top Panic-grass Red-top Panic-grass Red-top Panic-grass
Flower spike
Florets close-up
Leaf
Leaf ligule

Long-leaved Panic-grass      Coleataenia longifolia

A clump-forming species, most often found in more or less permanent wetland areas in the north of the county, especially in old cranberry bogs. Flowers July to September. Often confused with Red-top Panic-grass and formerly the two were considered to be the same species. In comparison, Long-leaved Panic-grass tends to be a shorter species with paler florets, and its leaf ligule is a row of short hairs, while the leaf ligule of Red-top Panic-grass is membranous.
Long-leaved Panic-grass Long-leaved Panic-grass Long-leaved Panic-grass
Habit
Flower spike
Florets close-up

Beaked Panic-grass      Coleataenia anceps

Scattered throughout the county in damp, often shady, places. Flowers July to September. Differs from similar species in having florets that project out at an angle to the main stem.
Beaked Panic-grass Beaked Panic-grass Beaked Panic-grass Beaked Panic-grass
Flower spike
Florets close-up
Leaf
Leaf ligule

Diffuse Crab-grass      Digitaria cognata

(Fall Witchgrass) A common and widespread species, found in dry, sandy fields, roadsides and other grassy places. Flowers June to October. A plant of uncertain affinities which has variously been placed in Digitaria, Panicum and Leptoloma. It has the look of the so-called witch-grasses of the genus Panicum so is placed here next to them. This grass is hard to miss in the fall when sometimes quite extensive colonies of short plants paint patches of the ground bright pink. Flower starts off narrow and broom-like, but branches gradually open to a right angle from the main stem. The flowers are tiny and carried on the ends of very long branchlets.
Diffuse Crab-grass Diffuse Crab-grass Diffuse Crab-grass Diffuse Crab-grass
Habit
Young flower spike
Florets close-up
Hair tufts in axils
of flower head