Pteridium


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Related to Pteridium: Bracken fern

Pteridium

a fern in the family Dennstadiaceae.
The fern is classified by some authorities as more than one species including: P. aquilinum, P. esculentum, P. revolutum, P. yarrabense. Called also bracken. It causes poisoning in several unique ways: (1) Ingestion by cattle over a short period causes depression of bone marrow activity, leading to pancytopenia evidenced principally as ecchymotic hemorrhages in mucosae and terminal septicemia. Severe diarrhea and dysentery may be terminal events. Ingestion over a long period causes proliferative lesions in and bleeding from the urinary bladder mucosa. See enzootic hematuria. Bright blindness of sheep also occurs when intake of bracken is prolonged. There is also a relationship between access to bracken and a higher than normal occurrence of intestinal carcinoma in ruminants. (2) A thiaminase in bracken causes a clinical syndrome of thiamin deficiency in horses. Signs are muscle tremor, incoordination, frequent falling and bradycardia and cardiac irregularity.
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Pteridium aquilinum.By permission from Knottenbelt DC, Pascoe RR, Diseases and Disorders of the Horse, Saunders, 2003
References in periodicals archive ?
Delarbre 35 Pteridium aquilinum Polypodiaceae Dhekia shak 36 Eichhornia crassipes Pontederiaceae Kochuripana (Mart.
Few of these fern nectaries have been described anatomically, with the notable exception of those of Pteridium, which have been described in ultrastructural detail (Power and Skog, 1987; Rumpf et al.
Plagiogyria euphlebia produces an irregular nucleus and obvious nuclear evaginations in the maturing egg, which resemble the derived ferns Pteridium aquilinum (Bell and Miilethaler, 1962b; Bell, 1972; Bell and Duckett, 1976; Bell, 1983), Dryopteris filix-mas (L.
owner of good points de la Sota customs) --Menstrual analgesic, treatment of excessive menstruation and female sterility Pteridium amambai rata --Menstrual analgesic arachnoideum (hard fern) (Kaulf.
Among the ferns, the anatomy of nectaries of Pteridium has been studied in the most detail.
flabellulatum possesses distinctive evaginations, similar to those in other leptosporangiate ferns so far investigated, including Pteridium aquilinum (Bell and Mulethaler, 1962b; Bell and Duckett, 1976), Dryopteris filix-mas (L.
The environment in which prothallia can establish successfully may differ greatly from the environment of the mature colonies, as is the case for Pteridium aquilinum (L.
The effect of spore density on germination and development in Pteridium, monitored using a novel technique.
Nucleotide sequences encompassing the chloroplast rps4 gene and the rps4-trnS intergenic spacer were obtained for several specimens representing North American and Hawaiian members of Pteridium aquilinum (ingroup), as well as Pteridium esculentum (outgroup).
The presence of vessel elements was documented in genera such as Pteridium, Selaginella, Equisetum and Marsilea and consisted of cells with scalariform to simple perforation plates (Duerden, 1940; Bierhorst, 1958; White, 1960).
In contrast, land managers search for effective herbicides to control some of the problematic weedy ferns such as Pteridium aquilinum (L.