flow ered ▁male ▁st amin ate ▁( male ) ▁head . ▁ ▁Flor al ▁structures ▁▁ ▁The ▁distingu ishing ▁characteristic ▁of ▁A ster aceae ▁is ▁their ▁infl ores c ence , ▁a ▁type ▁of ▁special ised , ▁composite ▁flower ▁head ▁or ▁pseud anth ium , ▁techn ically ▁called ▁a ▁cal ath ium ▁or ▁capit ul um , ▁that ▁may ▁look ▁super f icial ly ▁like ▁a ▁single ▁flower . ▁The ▁capit ul um ▁is ▁a ▁contract ed ▁rac eme ▁composed ▁of ▁numerous ▁individual ▁sess ile ▁flowers , ▁called ▁flor ets , ▁all ▁sharing ▁the ▁same ▁re cept acle . ▁ ▁A ▁set ▁of ▁b ract s ▁forms ▁an ▁invol u cre ▁surrounding ▁the ▁base ▁of ▁the ▁capit ul um . ▁These ▁are ▁called ▁" phy ll aries ", ▁or ▁" in vol uc ral ▁b ract s ". ▁They ▁may ▁simulate ▁the ▁sep als ▁of ▁the ▁pseud anth ium . ▁These ▁are ▁mostly ▁her b ace ous ▁but ▁can ▁also ▁be ▁bright ly ▁col oured ▁( e . g . ▁Hel ich ry sum ) ▁or ▁have ▁a ▁sc ari ous ▁( d ry ▁and ▁memb ran ous ) ▁texture . ▁The ▁ph yll aries ▁can ▁be ▁free ▁or ▁f used , ▁and ▁arranged ▁in ▁one ▁to ▁many ▁rows , ▁over la pping ▁like ▁the ▁t iles ▁of ▁a ▁roof ▁( im br icate ) ▁or ▁not ▁( this ▁variation ▁is ▁important ▁in ▁identification ▁of ▁tribes ▁and ▁gener a ). ▁ ▁Each ▁fl oret ▁may ▁be ▁subt ended ▁by ▁a ▁b ract ,