Q is for……… Quercus

A guest blog by Fernanda Castano, a paleontologist from Argentina. @ferwen on Twitter and blogger at paleonerdish.wordpress.com

The genus Quercus, in the family Fagaceae, is commonly referred to as oak. The group comprises more than 500 species and several hybrids and includes deciduous and evergreen species. The genus is native of the Northern Hemisphere and is therefore a genus that migrated during the Pleistocene, from the cool northern temperature zone to the tropics in the south.

Although the geological history of this genus could be traced back to the early Paleocene, the earliest reliable Quercus fossil in North America is from the Middle Eocene Oregon flora.

The leaves are spirally arranged and have various shapes, colors and textures with the margins entire, lobed, or toothed. The fruit is a nut called an acorn. The leaves and acorns of the oak posses a toxicity risk due the presence of tannic acid and may cause kidney damage and gastroenteritis. The pollen grain, Quercoidites, is tricolporate.

Oak wood was used in the construction of European timber-framed buildings and for the construction of ships until the 19th century.

In Greek mythology, the oak is the tree sacred to Zeus, while in the Norse mythology, the oak was sacred to the thunder god, Thor. Today, the oak is still a symbol of strength and endurance and has been chosen as the national tree of many countries.

Foliage and acorns of Quercus robur. From Wikipedia Commons.

Foliage and acorns of Quercus robur. From Wikipedia Commons.

Quercoidite pollen grain (Miocene) From Taylor et al, 2009.

Quercoidite pollen grain (Miocene) From Taylor et al, 2009.

Major Oak in Sherwood  Forest, Nottinghamshire. According to folklore, it was used by Robin Hood for shelter. From Wikipedia Commons

Major Oak in Sherwood Forest, Nottinghamshire. According to folklore, it was used by Robin Hood for shelter. From Wikipedia Commons

References:

Edith L. Taylor,Thomas N. Taylor,Michael Krings, 2009, Paleobotany: The Biology and Evolution of Fossil Plants, Academic Press.

Xing et al, 2013, A new Quercus species from the upper Miocene of southwestern China and its ecological significance, Review of Palaeobotany and Palynology, Elsevier.

Botanising Israel, an epic adventure of war and wildflowers, part 4

From our base at En Gedi we headed to Jerusalem for a day, the friends we were in Israel with wanted to see the culture and sights of the worlds oldest city and we took the opportunity to visit Jerusalems Botanic Gardens in the hope of seeing some of those illusive Iris. We got there to find that the botanic garden had experienced the worst snow it had ever seen just a couple of months earlier and was in the process of a major clearup opperation. However the extreme weather hadn’t stopped the native plants from putting on a show.

the walls of Jerusalem are full of wildflowers

the walls of Jerusalem are full of wildflowers

Onosma orientalis growing out of the city walls

Onosma orientalis growing out of the city walls

devistation at Jerusalem Botanic gardens

devistation at Jerusalem Botanic gardens

The introduced Oxalis pescaprae putting on a show

The introduced Oxalis pescaprae putting on a show

 

Almost the first thing we saw on entering the gardens was a display containing native israeli wildflowers.

Iris atropurpurea on display just inside the garden entrance

Iris atropurpurea on display just inside the garden entrance

Iris mariae our very own Oncocyclus iris in flower at Jerusalem Botanic gardens

Iris mariae, our very own Oncocyclus iris, in flower at Jerusalem Botanic gardens

 

Tulipa sylvestris

Tulipa sylvestris

 

Astragalus cretaceus

Astragalus cretaceus

peaonia mascula

peaonia mascula not yet in flower.

Salvia bractiata an extinct native being planted out in the garden having been rescued from oblivion.

Salvia bractiata an extinct native being planted out in the garden having been rescued from oblivion.

Salvia bractiata conservation bed

Salvia bractiata conservation bed

a very small plant with a big heap of hope, Salvia bractiata

a very small plant with a big heap of hope, Salvia bractiata

Narcissus tazetta the Israeli native Narcissus species

Narcissus tazetta the Israeli native Narcissus species

scilla hyacinthoides

scilla hyacinthoides

Iris atropurpurea

Iris atropurpurea

JERUSALEM

JERUSALEM

To be continued………