ing ▁in ▁the ▁S ich uan ▁and ▁Y unn an ▁provinces ▁of ▁China . ▁Most ▁members ▁of ▁the ▁g inger ▁family ▁( Z ing iber aceae ), ▁to ▁which ▁it ▁belongs , ▁are ▁tropical , ▁but ▁R . ▁h ume ana , ▁like ▁other ▁species ▁of ▁Ros co ea , ▁grows ▁in ▁much ▁col der ▁mountain ous ▁regions . ▁It ▁is ▁sometimes ▁grown ▁as ▁an ▁orn amental ▁plant ▁in ▁gard ens . ▁ ▁Description ▁ ▁Ros co ea ▁h ume ana ▁is ▁a ▁per enn ial ▁her b ace ous ▁plant . ▁Like ▁all ▁members ▁of ▁the ▁genus ▁Ros co ea , ▁it ▁dies ▁back ▁each ▁year ▁to ▁a ▁short ▁vertical ▁rh iz ome , ▁to ▁which ▁are ▁attached ▁the ▁t uber ous ▁roots . ▁When ▁growth ▁begins ▁again , ▁" pse ud ost ems " ▁are ▁produced : ▁structures ▁which ▁res emble ▁st ems ▁but ▁are ▁actually ▁formed ▁from ▁the ▁tight ly ▁wrapped ▁bases ▁( she ath s ) ▁of ▁its ▁leaves . ▁In ▁the ▁case ▁of ▁R . ▁h ume ana , ▁the ▁flowers ▁appear ▁before ▁the ▁leaves ▁are ▁fully ▁grown . ▁Pl ants ▁are ▁usually ▁ 1 3 – 2 5   cm ▁tall , ▁with ▁four ▁to ▁six ▁leaves . ▁Each ▁leaf ▁has ▁a ▁small ▁lig ule , ▁extending ▁to ▁about ▁ 2   mm . ▁The ▁bla de ▁of ▁the ▁leaf ▁( the ▁part ▁free ▁from ▁the ▁pseud ost em ) ▁is ▁usually ▁ 1 0 – 3 0   cm ▁long ▁by ▁ 3 – 6  