Gee, but it’s almost freezing!
Posted on January 6, 2008 by seedsaside
But that’s it. This moss cover is These mosses are growing sporophytes in mid-winter. Sure, it’s hardly cold here (between 5 and 10 Celsius the very last days), but still, it’s been freezing cold just a week ago. That’s what can be called a cold meiosis! I wonder if this is just some species specific trick or if many other mosses just do that, as if frost were a bad joke…
Filed under: English, Plant stuff
There are quite a number of moss species that have overwintering sporophytes . For these taxa fertilization occurs during the fall, when the ambient water is still liquid. The mosses have flagellated and motile sperm, so liquid water is essential for reproduction. Then the sporophyte survives the winter at a small embryo or spear stage. The light signal from lengthening days, in the spring, stimulates them to complete development and produce a capsule full of spores.
It does seem a little early for capsules though. Perhaps the stimulus for this species is temperature and we can blame global warming. Or we did just pass the winter solstice and the days are lengthening, maybe this species just needs the days a little longer to trigger capsule production.
I would be interested to know what species this is and if you found any other species with capsules at this time of year. In Connecticut (USA) I have yet to see any sporophytes that have expanded to produce capsules this early in the season.
Thanks for the info… This amazing to think of meiosis happening in wintertime. These species are from France (30 kms West of Paris), where climate is soft in winter (but still cold and regularly freezing), but temperature may have been rising over the last decade because of air pollution from the city…