If you are interested in plants, the Festival of the Trees Blog Carnival is fun to browse through. 
The newest carnival is up at Treeblog.
If nothing else, go see the fantastic photographs Ash found on Flickr.
Category: Learning Outdoors (Page 28 of 63)
The mystery seeds from last week were from a pine, believe it or not.
We did a common experiment to see whether open, dry pine cones do indeed close up when placed in water. The seeds floated out of the first cone when we first placed it into the water.
And then the pine cone did close up, remarkably quickly.
We looked at another open pine cone.
You can just see tips of the seed wings on the hard pine cone scales. Those wings help them disperse in the wind, like the maple keys they resemble.
Here are pine cones on the ground. What kind of weather have we been having? (Hint: see above.)
Pine cones are often seen hanging on the tree. It takes at least nine months for the seeds to mature within the female cones. Some species require up to two years for the seeds to mature.
Even once the seeds are mature, certain types of pine cones remain closed until they are exposed to the intense heat of a fire.
The seed itself is within the winged structure. If you were to remove the coating, it would look like a pine nut:
Although the tree associated with the Sonoran desert is usually the saguaro cactus, there are a few pine trees that are planted in urban areas. Two pines that can grow in hot dry conditions are the Mondel or Afghan pine, Pinus eldarica, and the Aleppo pine, Pinus halepensis. They are not native North America, but to regions around the Mediterranean.
What kind of pine trees grow where you live? Have you ever seen a pine seed?
Related activities:
Fibonacci numbers in pine cones
Have you ever tried a pine nut? Look for some in you grocery store and give them a try.
(I apologize to anyone who gets this as a duplicate via RSS feed. The original post was lost during a recent crash of the server.)
The mystery seed 8 last week was indeed a maple key, a silver or swamp maple (Acer saccharinum) seed to be exact.
Silver maples are commonly grown as ornamental trees in the eastern United States and southeastern Canada. They have lovely, delicate leaves with deeply cut lobes.
It is easy to find silver maple keys because they are the largest winged seeds of the native maples and because the trees produce a lot of them. Many birds and small mammals use the seeds for food.
Hopefully a few of those seeds becomes a new tree.
For more information, see Roberta Gibson Writes.