Glyceria aquatica (glyceria). Related species: G. striata (tall
mannagrass). A member of the plant family GRAMINEAE. Perennial glabrous aquatic herb,
favouring wet areas, ponds, fens and slow flowing rivers. Long, upright green leaves;
flowers, which are in spikelets, are pale green with purple spots.
Animals most affected
Ingestion of the fresh plant (especially during drought when only marshy areas remain
Contains a cyanogenetic heteroside, dhurrine. The hydrogen cyanide (HCN) content
in fresh plant material varies from 0.06—0.2g/kg.
Oral doses in g fresh plant per kg body weight:
Clinical signs present almost immediately:
death in 1-2 minutes, preceded by a few convulsions and paddling movements of the
When ingestion is occasional:
dullness, weakness, torpor, mydriasis;
severe dyspnoea, tachycardia;
congestion and cyanosis of the mucous membranes;
rapid death, frequently results due to asphyxia.
Where the quantity of plant ingested is minimal:
recovery within a few hours without sequelae.
severe congestion and cyanosis of the mucous membranes;
Almost impossible to administer as the onset of clinical effects is too rapid. The
following may be attempted:
iv sodium hyposulphite, 3 g/100 kg;
iv sodium nitrite (10% solution), 15 ml/ 100kg;
iv EDTA, 2~25 mg/kg;
contents of the stomach or rumen to confirm plant poisoning from any fragments
of Glyceria aquatica;
check the level of HCN in the contents of the stomach or rumen; as the compound
is highly volatile, it is essential that a very fresh sample is obtained, or
that it is frozen immediately.