▁f ern ▁of ▁the ▁family ▁O phi og loss aceae . ▁It ▁is ▁a ▁pan - t rop ically ▁species ▁categor ised ▁as ▁least ▁concern ▁by ▁the ▁IU CN ▁( 2 0 0 1 ). ▁ ▁Description ▁O phi og los sum ▁l us itan icum ▁is ▁a ▁small ▁winter ▁annual ▁f ern , ▁and ▁consists ▁of ▁a ▁simple ▁ster ile ▁bla de ▁attached ▁to ▁a ▁sp ike - like ▁fert ile ▁bla de ▁with ▁between ▁three ▁and ▁eight ▁sun ken ▁sp or ang ia ▁on ▁either ▁side . ▁The ▁whole ▁plant ▁rarely ▁exceed s ▁a ▁height ▁of ▁ 2   cm . ▁ ▁This ▁species ▁has ▁a ▁chrom os ome ▁number ▁of ▁ 2 n ▁= ▁ 2 5 0 – 2 6 0 . ▁ ▁Distribution ▁O phi og los sum ▁l us itan icum ▁is ▁native ▁to : ▁Africa ▁and ▁India . ▁It ▁is ▁also ▁found ▁on ▁the ▁western ▁se ab o ard ▁of ▁Europe ▁( Gre at ▁Britain , ▁Spain ▁and ▁Portugal ); ▁the ▁Atlantic ▁Islands ▁( C ape ▁Ver de ▁and ▁the ▁Can ary ▁Islands ); ▁the ▁Middle ▁East ▁( Is rael ▁and ▁Iran ); ) ▁South ▁America ▁( Per u ▁and ▁Argentina ); ▁and ▁Austral asia ▁( Austral ia ▁and ▁New ▁Zealand ). ▁ ▁The ▁distribution ▁in ▁Britain ▁is ▁restricted ▁to ▁one ▁small ▁area ▁of ▁coast al ▁he ath ▁on ▁St ▁Ag nes , ▁Is les ▁of ▁Sc illy ▁where ▁it ▁was ▁discovered ▁by ▁John ▁R aven ▁in ▁ 1 9 5 0 . ▁It ▁grows ▁in