Ginkgo biloba

maidenhair tree

Ginkgoaceae

The Basics

Plant Guide

The Ginkgo nut-like gametophytes inside the seeds are a traditional Chinese food often served at weddings. They are believed to have health benefits or have aphrodisiac qualities...Ginkgo is also added in small amounts to energy drinks, but it does not produce a noticeable effect, except as a placebo, or marketing tool from Ginkgo being listed on the label.

The extract from the Ginkgo leaves contains flavonoid glycosides, and ginkgolides...There are three effects on the human body: (1) it improves blood flow (including microcirculation in small capillaries) to most tissues and organs; (2) it protects against oxidative cell damage from free radicals (antioxidant); and (3) it blocks many of the effects of PAF (platelet aggregation, blood clotting) that have been related to the development of a number of cardiovascular, renal, respiratory and CNS (Central Nervous System) disorders. (Plant Guide)

Identification

The Ginkgo is a medium to large tree that reaches 20-35m tall, although some specimens in China are over 50m tall. Ginkgo trees often have angular crown and long, somewhat erratic branches...The leaves are unique among seed plants, being fan-shaped with veins radiating out into the leaf blade, sometimes bifurcating (splitting), but never anastomosing to form a network. Two veins enter the leaf blade at the base and fork repeatedy in two. This is known as dichotomous venation. (Plant Guide)

Threats

The Ginkgo is disease resistance, insect-resistant wood and has the ability to form aerial roots and sprouts. This means the Ginkgo lives long, with some specimens claimed to be more than 2,500 years old; a 3,000 year-old. (Plant Guide)

Reproduction

Ginkgos are dioecious with separate female and male sexes. Male plants produce small pollen cones with sporophylls, each bearing two microsporangia spirally arranged around a central axis. Female plants do not produce cones. Two ovules are formed at the end of a stalk, and after pollination, one or both develop into seeds.

The seed is 1.5-2 cm long. Its outer layer, the sarcotesta is light yellow-brown, soft, and fruit-like. It is plum like and attractive, but the seedcoat contains butanoic acid, and smells like rancid butter when fallen on the ground. Beneath the sarcotesta is the hard sclerotesta, and a papery endotesta and nucellus.

The fertilization of ginkgo seeds is unusual in that it utilizes motile sperm; cycads are the only other seed plants with this feature. When the pollen reaches the pollen chamber, two sperm are produced, one of which goes on to fertilize the ovule. The fertilization of ginkgo seeds is complete by the time they fall in autumn. (Plant Guide)

Species Distribution

The ginkgo is a drought-resistant, adaptable species, and is very cold hardy thriving. It is also very pH adaptable, tolerates air pollution and soil salt pollution, making it an ideal candidate for adverse urban conditions. It will grow in almost any conditions, it prefers deep, sandy, moist soil and requires full sun. (Plant Guide)

Citation

USDA Plant Database http://plants.usda.gov/characteristics.html USDA, NRCS. 2016. The PLANTS Database (http://plants.usda.gov, 4 February 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA.

Flora of North America http://www.efloras.org/flora_page.aspx?flora_id=1 Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 19+ vols. New York and Oxford.

Silvics of North America Burns, R.M., and B.H. Honkala. 1990. Silvics of North America (Volume 1: Conifers, Volume 2: Hardwoods). USDA Forest Service Agricultural Handbook 654.

Intermountain Herbarium http://intermountainbiota.org/portal/collections/harvestparams.php Consortium of Intermountain Herbaria. 2016. http//:intermountainbiota.org/portal/index.php. Accessed on February 04.

Burke Museum Plant Image Collection The plant image collection at the Burke Museum, University of Washington.

Jepson Manual http://ucjeps.berkeley.edu/eflora/ The Jepson Manual: Vascular Plants of California. B.G. Baldwin, D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken [editors]. 2012. 2nd edition, thoroughly revised and expanded. University of California Press, Berkeley, CA., hardcover; 1600 pages. ISBN-13: 978-0520253124.

USGS Plant Species Range Maps http://esp.cr.usgs.gov/data/little/ Critchfield, W.B., and Little, E.L., Jr., 1966, Geographic distribution of the pines of the world: U.S. Department of Agriculture Miscellaneous Publication 991, p. 1-97. Little, E.L., Jr., 1971-1978, Atlas of United States trees, volume 1,3,13,17, conifers and important hardwoods: U.S. Department of Agriculture Miscellaneous Publications.

Photo from Smithsonian National Museum of Natural History.