um ▁as ▁an ▁" orth ographic ▁variant ", ▁and ▁the ▁Index ▁N omin um ▁Gener ic orum ▁database ▁uses ▁the ▁sp elling ▁R ip og on um , ▁as ▁does ▁the ▁World ▁Check list ▁of ▁Selected ▁Plant ▁Famil ies ▁. ▁ ▁Ph y log eny ▁and ▁classification ▁Until ▁recently , ▁R ip og on um ▁was ▁included ▁in ▁the ▁family ▁Sm il ac aceae ▁( and ▁earlier ▁in ▁the ▁family ▁L ilia ceae ▁along ▁with ▁other ▁l ilio id ▁mon oc ots ) ▁but ▁it ▁has ▁now ▁been ▁separated ▁into ▁its ▁own ▁family ▁R ip og on aceae . ▁The ▁family ▁name ▁was ▁first ▁formally ▁defined ▁by ▁Con ran ▁and ▁Cl iff ord ▁in ▁ 1 9 8 5 . ▁Armen ▁Tak ht aj an ▁later ▁created ▁the ▁same ▁family ▁without ▁real ising ▁it ▁already ▁existed . ▁ ▁M ole cular ▁ph y log en etic ▁studies ▁since ▁the ▁early ▁ 2 0 0 0 s ▁have ▁consist ently ▁shown ▁a ▁close ▁relationship ▁between ▁the ▁four ▁families ▁R ip og on aceae , ▁Phil esia ceae , ▁Sm il ac aceae ▁and ▁the ▁modern ▁narrow ly ▁defined ▁L ilia ceae . ▁This ▁relationship ▁was ▁confirmed ▁in ▁a ▁ 2 0 1 3 ▁study , ▁which ▁produced ▁the ▁cl ad ogram : ▁ ▁The ▁authors ▁suggested ▁that ▁the ▁R ip og on aceae ▁and ▁Phil esia ceae ▁could ▁be ▁combined ▁into ▁a ▁single ▁family ▁based ▁both ▁on ▁the ▁gen etic ▁similarity ▁of ▁their ▁pl ast ids ▁and ▁common ▁morph ological ▁features . ▁The ▁AP