Conifers are noted for their seed cones (female) and much smaller pollen
cones (male). Most have long narrow leaves called "needles" but in some
the leaves are small triangular scales covering the twigs. The seed cones
often have many scales which may be woody, leathery or paper-like, but in
other genera the scales are fleshy and fused together so the cone resembles
[genus Araucaria of family Araucariaceae]
The photo shows the densely needled habit of these trees which are
now widely planted as ornamentals in the northern hemisphere from which
they have been absent since the demise of the dinosaurs about 65
million years ago.
[genus Juniperus of family Cupressaceae (cypress)]
[genus Pinus of family Pinaceae (pines)]
Pine nuts (officially a seed, not a nut) have been eaten since prehistoric times in Europe, Asia and North America. Today the sweet resinous seeds are somewhat costly and used mostly as a flavoring ingredient but Italian pesto sauce is often based on pine nuts (other nuts are also used).
Pine nuts from a number of species are available. In Europe it's mostly the Stone Pine (Pinus pinea) and in Asia the Korean Pine (Pinus koraiensis) and Chilgoza Pine (Pinus gerardiana). Siberian Pine (Pinus sibirica) and a number of other varieties are also used. In North America seeds of various species of Pinon pines (subgenus Ducampopinus) are harvested.
The most common commercial pine nut is the Korean, a fairly large seed, followed by the Siberian, a fairly small seed. North American Pinon seeds are large but in very short supply, particularly due to forest destruction to make range land after WWII. Most now come from Mexico and the price is much higher than for Korean or Siberian seeds.
Warning: See Details and Cooking for description of problems with Chinese pine nuts (99+% of shelled pine nuts sold in the U.S.).
The soft layer between pine bark and the wood is also edible and has been used as a famine food. Pine needles are sometimes used as a flavoring.
The photo shows the end of a pine branch from a tree in my front yard
with tiny male cones at the center, a pine cone of unknown source and a
few whole seeds in the shell from that cone. The small shelled seeds were
commercially purchased and are from Siberian pines.
[genus Picea of family Pinaceae]