plant fibre for thread

[emitfudd]

I am crafting the bottom row of T3 clothing. I am trying to max all my stats as this may be the last set of clothing I need to craft. When crafting thread, it shows the available plant fibre I can use. I have some T4 Dahlia seeds and plants but they don't show up in the list to craft thread. I don't see any crafting station options to craft plant fibre, only animal fibre. What am I missing here?

[Powerferret]

You dont craft plant fiber, you harvest it. Crude fiber from regular plants, Holt bloom in forest, cinder strand in desert, titania's crown in swamp. Bound fiber from bound, obviously.
And 2 Teir 5 that randomly spawn, Luminous Spore (T5, any Swamp; looks like a giant blue mushroom tree)
Britomart's Locks (T5, any Ascended Desert; looks like a termite hill with white tufts)