Tall manna grass-Glyceria grandis S. Wats.-Poisonous plant

Tall manna grass

General poisoning notes:

Tall manna grass (Glyceria grandis) is a native and naturalized grass found across Canada. This plant has caused sickness and death in a herd of cattle in British Columbia. The poisoning took place early in the season, suggesting that the amount of cyanogenic potential decreases in the plant later in the season (Puls et al. 1978).

Description:

Plants perennial, rhizomatous. Culms 70-150 cm, erect or the bases reclining on the ground but with the tip ascending. Leaves with the sheaths closed for at least half their length, the upper sheaths closed to near the tops, all sheaths glabrous and smooth to minutely roughened; ligules 2-6 mm long, truncate or rounded, those of the lower leaves stiff at the base, those of the upper ones flexible throughout; blades 22-44 cm long, 5-13 mm wide. Flowering heads 25-37 cm long, open; branches spreading to drooping. Spikelets (3.9-) 4.5-6.6 mm long, 1.5-2.3 mm wide, with (3-) 4-7 florets. Glumes acute, the midvein extending to the tip; first glume 1.2-2 mm long; second glume 1.7-2.3 mm long; lemma 1.8-2.5 mm long, prominently (5-) 7-veined, the veins often slightly roughened, the area between the veins smooth, the tip flat at maturity; palea equaling to slightly longer than the lemma; anthers 3. Chromosome number 2n = 20.

Nomenclature:

Scientific Name: Glyceria grandis S. Wats.

Common Name: Reed Manna Grass, American manna grass, giant glyceria, giant manna grass

Vernacular name(s): tall manna grass

Scientific family name: Gramineae

Vernacular family name: grass

Geographic Information

Alberta, British Columbia, Manitoba, New Brunswick, Northwest Territories, Ontario, Prince Edward Island, Quebec, Saskatchewan.

Toxic parts:

Leaves, stems.

Notes on Toxic plant chemicals:

An unknown cyanogenic glycoside that can be converted to cyanide in the animal body is found in tall manna grass. Cyanide in concentrations of more than 10 ppm was detected in whole blood taken from poisoned cattle (Puls et al. 1978).

Toxic plant chemicals:

Unknown chemical.

Animals/Human Poisoning:

Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.

Cattle

General symptoms of poisoning:

death

gait, staggering

liver, congestion of.

Notes on poisoning:

Symptoms included staggering and death. The liver was congested and lung lobes showed interlobular edema and slight emphysema. Animals that were staggering, but did not fall, recovered (Puls et al. 1978).