A mechanism is proposed for the creation of taenia on the capillitium of Tr
ichiales. Polymerization of elater wall material forms spiralling fibrils,
releasing water which passes by osmosis into the lumen. This extends the bu
lbous extremities of Trichia decipiens elaters producing the characteristic
ally tapered tips. The edge of the elater shrinks as water is lost, and is
moulded by the fibrils into a system of taenia.