28000 km2 is the approximate area of the country where the flower species Lobelia columnaris can be found (other than Cameroon).
 It is the only giant Lobelia occurring in West Africa and is found in Cameroon and Equatorial Guinea. 
Equatorial Guinea (Spanish: "Guinea Ecuatorial" , French: "Guine quatoriale" , Portuguese: "Guin Equatorial" ), officially the Republic of Equatorial Guinea (Spanish: "Repblica de Guinea Ecuatorial" , French: "Rpublique de Guine quatoriale" , Portuguese: "Repblica da Guin Equatorial" ), is a country located in Central Africa, with an area of 28000 km2 . 
