Azolla mexicana not A. filiculoides, two-thirds confident.
Azolla Post 1 of 2:
Wacky Salviniales, Azolla Taxonomy, and Azolla Climate Change
Mexican mosquito fern, water fern
British Columbia to Mexico, east to Texas. Maybe also US Great Plains.
Azolla contains approx. seven species of aquatic ferns plus at least six extinct species.
Two Pacific Northwest species:
A. mexicana syn. Azolla microphylla
& A. filiculoides.
Azolla mexicana is distinguished from A. filiculoides by having multicellular hairs on the leaves and pits on the megaspores.
Maybe AZMA "fronds" and foliage also appear to be more tightly packed?
Order Salviniales are all aquatic and differ from other ferns in being #heterosporous: producing two different types of spores, megaspores and microspores; which develop into two different types of gametophytes, female and male, and the gametophytes are #endosporic.
This set of traits make Salviniales more similar to spermatophytes and different from all other ferns.
Spermatophytes are the seed producing plants and include the Cycado, Ginkgo, Pino, Gneto, Angio, and Pteridospermato DIVISIONS.
Spermatophytes evolved after a whole genome duplication event ~319 million years ago.
More recently, ~50 million years ago, Azolla radically altered Earth's climate; sequestering enough carbon to plummet Earth's atmospheric CO2 levels by 80%, from 3500 ppm to 650 ppm.
This changed the planet from a greenhouse earth lacking polar ice caps to today's icehouse earth.
The ancient Azolla mega bloom occurred within a land locked Arctic Ocean and lasted over 100,000 years. Ancient Azolla is a significant contributor to today's Arctic petroleum caches.
Learn more about this event from @the_buckeye_botanist
#AZME #AZMI OBL-WMVC
syn. Azolla microphylla
#Salviniaceae frmr. #Azollaceae
#Salviniales frmr. #Hydropteridales
& incl. frmr #Marsileales
#natant #natantfern #floatingfern
#fernwhat! #ferndork #ferndorky
#ferndive #Arcticoil #fernhistory