y ta ▁by ▁Har lan ▁Parker ▁B anks ▁in ▁ 1 9 6 8 ▁under ▁the ▁name ▁Rh yn i oph yt ina . ▁The ▁original ▁definition ▁was : ▁" pl ants ▁with ▁n aked ▁( lack ing ▁emer gen ces ), ▁dich ot om izing ▁axes ▁bearing ▁sp or ang ia ▁that ▁are ▁terminal , ▁usually ▁fus iform ▁and ▁may ▁de h isce ▁longitud in ally ; ▁they ▁are ▁dimin utive ▁plants ▁and , ▁in ▁so ▁far ▁as ▁is ▁known , ▁have ▁a ▁small ▁ter ete ▁x yle m ▁str and ▁with ▁a ▁central ▁proto x yle m ." ▁With ▁this ▁definition , ▁they ▁are ▁pol ys por ang i oph y tes , ▁since ▁their ▁sp or oph y tes ▁consisted ▁of ▁branch ed ▁st ems ▁bearing ▁sp or ang ia ▁( sp ore - form ing ▁org ans ). ▁They ▁lack ed ▁leaves ▁or ▁true ▁roots ▁but ▁did ▁have ▁simple ▁v asc ular ▁t issue . ▁Inform ally , ▁they ▁are ▁often ▁called ▁rh yn i oph y tes ▁or , ▁as ▁mentioned ▁below , ▁rh yn i oph y to ids . ▁ ▁However , ▁as ▁originally ▁circ ums cribed , ▁the ▁group ▁was ▁found ▁not ▁to ▁be ▁mon oph y let ic ▁since ▁some ▁of ▁its ▁members ▁are ▁now ▁known ▁to ▁lack ▁v asc ular ▁t issue . ▁The ▁definition ▁that ▁seems ▁to ▁be ▁used ▁most ▁often ▁now ▁is ▁that ▁of ▁D . ▁Edwards ▁and ▁D . S . ▁Edwards : ▁" pl ants ▁with ▁smooth ▁axes ,