Sunday, March 30, 2014

Visiting Northern Florida--Forest Walk at Birdsong

 In February, 2014, I was in northern Florida and visited Birdsong Nature Center, just north of Tallahassee at the southern edge of Georgia.
the forest 
the forest
The pine forests of north Florida and south Georgia were once part of a broad belt of forest across the southern U.S. Much of that area belonged to plantations that after the Civil War became hunting reserves for very rich northerners. That preserved them into the middle of the 20th century. Much of the southern pine forest has been lost to development but some remains as private and public reserves. 

Sunday, March 23, 2014

Plant Story -- Osage-Orange and the Animals of the Pleistocene

Osage-oranges  on the ground
 on the ground
Osage-orange, Maclura pomifera, is a tree endemic to (native only in) North American. Its range. when Europeans first encountered it, was small: the area where Arkansas, Texas and Oklahoma meet. Its habitat is described as woods, forest edges and streams. Widespread planting of Osage-orange for fences in the 1850s-1870s has greatly expanded its distribution.

I talked about Osage-orange's interesting wood previously (link). But Osage-orange has memorable fruits. See Osage-orange fruit They are bigger than oranges. The outer rind is warty. Inside it is more solid than an orange, with a row of small seeds. (Gray's Manual of Botany calls the fruits "disappointingly dry and hard" inside). Not much of anything eats them. People don’t eat them, some horses like them, deer eat a few and determined squirrels will tear them open and eat the seeds, but still the big fruits pile up at the base of the tree. 

Mostly we don't think about what we see and ask "why?" But why does Osage-orange make a huge fruit? Plants are rooted. To get to new areas, something (wind, water, an animal) has to carry the seeds away. Osage-orange fruits seem horribly inefficient at dispersing the plant. 

The current answer is: the fruits evolved to be eaten by animals that have gone extinct.

Sunday, March 16, 2014

Visiting Tierra del Fuego--A Walk on Cape Horn

beach at Cape Horn
beach at Cape Horn
In November of 2009 I boarded the Via Australis as part of National Geographic trip to sail the Beagle Channel from Argentine Patagonia to Chilean Patagonia, not around Cape Horn but through the safer (though not especially safe) interior waterways. Before sailing westward, however, we were offered the opportunity to walk on the island at the tip of South America, Cape Horn. (Take Google Maps to the tip of South America link then zoom out).

Sunday, March 9, 2014

Visiting Northern Florida--ooh! Magnolias!

magnolia flowers emerging from Spanish moss
magnolia flowers emerging from Spanish moss

At the end of February, I visited Tallahassee Florida. Tallahassee gets frosts and snow every decade or so--including this year, so in many ways it was still very early spring, but some magnolias were in full bloom. I was enchanted. Here are pictures of magnolias in flower in Tallahassee and especially at Maclay Gardens

a single magnolia flower
a single magnolia flower

Sunday, March 2, 2014

Plant Story--The Many Uses of Osage-Orange, Maclura pomifera, Wood

Osage-orange fruits
Osage-orange trees with fruits
Planted all over the U.S., Osage-orange, Maclura pomifera is a curious native North American tree. Clearly related to mulberries despite its huge fruit it is classified in the mulberry family, Moraceae. For a long time it was the only member of its genus, Maclura. Recently, genetic and molecular studies have recognized about a dozen relatives from around the world and added them to the genus. In particular the South American tree Maclura tinctoria, called old fustic, dyer's mulberry and toothache tree, is now included in the genus Maclura so Osage-orange is no longer the only Maclura species. 

Osage-orange grows to be a substantial tree getting 30' tall. The current North American record is held by a tree at Patrick Henry National Memorial in Red Hill, Virginia which they report as 55' high with branches that span 90' (link). What people usually remember about Osage-orange are the fruits. They are very distinctive: bigger than oranges, ripening to an orange color, but on the inside unappealing. pictures on Google  The tree grew in the lands of the Osages, and so the tree was named Osage-orange. (People don't usually put the hyphen in there, but it isn't in any way a citrus fruit or related to edible oranges, so the hyphen is helpful).