A ginkgo leaf
Ginkgo (or maidenhair) is the common name for the tree Ginkgo biloba.
The Ginkgo family first appeared 200 to 225 million years ago, in the Paleozoic era. Ginkgoes were widespread about 100 million years ago, but now they only exist in a wild state in a remote region in China. However, they have been widely exported to the rest of the world as an ornamental tree, where ginkgoes are also known as "maidenhair" trees. The ginkgo is the only living member of its phylum.
Ginkgoes are unique in the plant kingdom, as evidenced by their sole membership of the Ginkgophyta phylum. For one thing, they are possibly the only plants to have centrioles. Ginkgoes represent the only extant link between lower and higher plants because of their method of fertilization, which involves swimming sperm.
Ginkgoes are dioecious, though the two sexs are similar in morphology until about 30 years old. Among other identifying characteristics, female trees develop edible but foul-smelling seeds in the autumn. In the spring, older ginkgoes will develop sporangia.They are a resilient species, able to withstand city pollution and fungus and insect attacks. One ginkgo in Hiroshima, Japan even managed survive the atomic blast that leveled much of the city in World War II.
| North American EGb Study Group:
|309 patients with mild to severe dementia||120 mg/d||beneficial|
|203 "healthy adults older than 60 years with Mini-Mental State Examination scores greater than 26||40 mg 3 times per day||not beneficial|
|3069 "community volunteers aged 75 years or older with normal cognition or mild cognitive impairment"||120 mg twice daily||not beneficial|
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- Gorman, C. (1997). More than a funny name. Time. November 3, p. 53.
- DeKosky ST, Williamson JD, Fitzpatrick AL, et al (November 2008). "Ginkgo biloba for prevention of dementia: a randomized controlled trial". JAMA 300 (19): 2253–62. DOI:10.1001/jama.2008.683. PMID 19017911. Research Blogging.
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