ile ▁stam ens , ▁which ▁are ▁merged ▁at ▁their ▁base ▁into ▁a ▁ring ▁or ▁merged ▁at ▁their ▁base ▁in ▁tri os ▁with ▁the ▁middle ▁fil ament ▁longer ▁than ▁the ▁others , ▁except ▁for ▁M . ▁bre vi ro str ata ▁with ▁only ▁five ▁stam ens . ▁E rod ium ▁has ▁five ▁st amin odes ▁and ▁five ▁fert ile ▁stam ens , ▁without ▁wings . ▁Pel arg on ium ▁has ▁ten ▁fil aments ▁without ▁wings , ▁between ▁two ▁and ▁seven ▁of ▁which ▁are ▁to pped ▁by ▁an thers , ▁while ▁the ▁remaining ▁three ▁to ▁eight ▁are ▁st amin odes ▁lack ing ▁an thers , ▁but ▁it ▁can ▁easily ▁be ▁distinguished ▁by ▁having ▁only ▁one ▁narrow ▁t ube - like ▁ne ct ary ▁inside ▁what ▁looks ▁like ▁the ▁flow erst alk . ▁ ▁Tax onomy ▁ ▁Ger ania ceae ▁and ▁Franco aceae ▁are ▁the ▁two ▁families ▁included ▁in ▁the ▁order ▁Ger an ial es ▁under ▁the ▁Ang ios perm ▁Ph y log eny ▁Group ▁( AP G ) ▁classification ▁( AP G ▁IV ). ▁There ▁has ▁been ▁some ▁uncertainty ▁in ▁the ▁number ▁of ▁gener a ▁to ▁be ▁included . ▁Stevens ▁gives ▁seven ▁gener a ▁listed ▁here , ▁while ▁Christ en h usz ▁and ▁By ng ▁state ▁five ▁gener a . ▁ ▁Stevens ▁also ▁lists ▁four ▁syn onym s ▁of ▁Ger an ium : ▁Ger ani opsis ▁Chr tek ▁Ne uro phy ll odes ▁( A . ▁Gray ) ▁O . ▁D eg ener ▁ ▁Robert ian um ▁Pic ard ▁Robert iella ▁ ▁Hyp se och