Monday, August 22, 2011

Australian ferns: part III

In keeping with my trend of decreasing in size with these fern posts, this last one focuses on the truly tiny: gametophytes that we found growing on moist soil banks. Gametophytes are the free-living haploid stage of the fern life cycle, and in temperate climates they're usually pretty challenging to locate, since they're small, relatively ephemeral, and look just like mosses. In the tropics it's considerable easier to find them, and as soon as we started to hunt for them they started to pop out of the background. The photo above shows a large clump of gametophytes that may actually a single plant, or a bunch clumped together. That's a bit of moss sticking out of the back, not a sporophyte. The two photos below do show sporophytes starting to grow out of the gametophytes; in the first one the sporophyte is pretty small, and the large, heart-shaped plate-like structure below it is the gametophyte. In the second, the sporophytes are becoming more branched and the gametophyte is harder to make out in all the green, but it's still there!

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