Have anybody seen 'Baeothryon subcapitatum(Thwaites) T.Koyama' in the LFS. I saw it in the 58th issue of the Taiwan Aquarium world magazine. It is like a Giant Umbrella Hairgrass(Eleocharis vivipara) with off spring from tip of the leave but with a leave thickness of 2-3mm. and 50 cm high. It is not Isoetes sp.