moss mfriday #2: Takakia lepidozioides and Takakia ceratophylla
Takakia lepizioides. [image credit]
Takakia is an incredibly special genus of mosses, containing only 2 known species. Evolutionarily, it's the oldest extant species of plant on all of planet Earth, boasting an unbelievable 390 million years and still kicking. Their uniquely ancient characteristics earned Takakia species their own family, Takakiaceae.
The first discovered Takakia species, Takakia ceratophylla, was originally described as a liverwort by William Mitten in 1861, but upon further investigation by Dr. Noriwo Takaki in the mid-twentieth century, Takakia species were found to exhibit characteristics that no other plant on Earth possessed. It was only when a specimen of Takakia was discovered bearing moss-like archegonia and sporophytes that biologists were able to place Takakia firmly in the moss category.
Takakia leaves split into delicate filaments like fingers on a hand, a morphology that no other moss exhibits. They also completely lack any protective perichaetial leaves around their reproductive structures; the gametangia are instead are tucked into the angle formed where the stem and vegetative leaves connect. The sporophyte capsules that emerge rupture along the side when mature, rather than opening through an operculum (a lid), which is an uncommon trait attributed to mosses that evolved before the invention of the operculum.
[image credit]
Takakia is a fast-evolving genus, adapted to ultraviolet radiation, extreme temperature, and high altitudes. But climate change still threatens this beautiful, stubborn dinosaur. Bryologists estimate that by the end of the 21st century, its habitat will be reduced to only a couple thousand square kilometers - or it would, except that these same conservationists are hard at work cultivating Takakia and expanding its habitat. Just goes to show how much a small team's effort matters in the ongoing war against life's extinction. I can't imagine losing these precious species.
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