The Ponderosa tree in my back yard is clearly bearing two different kinds of pines this year (presumably it does every year, but I haven’t noticed it before). It turns out that they are male and female cones.
The female cone is the familiar pine cone; they are clustered on the lower part of the tree so that the pollen from the male cones will drift down and fertilize them. (Well, in theory. The cones on our tree are scattered throughout the tree but more on top than bottom.) Female pine cones generally start out green, soft, and sticky; after fertilization, they turn hard and brown to protect the seeds. Female cones grow for a few years while the seeds mature, then open up so the seeds can distribute on the wind.
In most pines, male pine cones are noticeably smaller than female pine cones, but that isn’t true on this tree – they are just as visible, but fluffy instead of spikey. They are mostly on the bottom half of the tree, but not completely.