Read on Twitter
It's #FernFriday!! This week on #51WeeksOfPteridophytes, we'll cover the Psilotaceae! There are two genera in this family, Psilotum and Tmesipteris (so basically the family of silent letters??), with around 17 species in total. Here is Psilotum nudum PC: @BethanyZumwalde 1/
Super weird, right!? So un-fern like! These ferns don't have true #roots and the jury is still out on their #leaves ( @avascog has transcriptomic evidence they are true leaves!). Each of those brown balls are actually called synangia- three fused sporangia, cross-section below: 2/
The other genus, Tmesipteris (miss-ip-teris), also has synagnia, but are two rather than three fused sporgangia. What look like leaves in the pictures below are actually flattened #stems! These cool plants are mostly restricted to Pacific Islands (e.g, New Zealand) 3/
Of course, we have to mention that these plants were once thought to be related to the earliest of the vascular land plants with the rhyniophytes (drawing below). While their #morphology might be similar, #molecular work places Psilotaceae squarely in the ferns. 4/
And finally I would be remiss if I didn't mention that Psilotum #gametophytes have a #symbiosis with arbuscular mycorrhizal fungi! These are some seriously cool plants :) Up next week: Ophioglossaceae! 5/ https://link.springer.com/article/10.1007/s10265-009-0234-8
