http://www.bbc.com/earth/story/20141121-the-rarest-plants-in-the-world
https://letitgrow.org/science-wellbeing/5-rarest-plants-world/
https://en.wikipedia.org/wiki/Encephalartos_woodii
http://www.iucnredlist.org/details/41889/0
https://en.wikipedia.org/wiki/Lotus_berthelotii
https://en.wikipedia.org/wiki/Anogramma_ascensionis
http://earthsky.org/earth/the-odd-life-of-an-underground-orchid
http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:60441188-2
https://en.wikipedia.org/wiki/Medusagyne
http://www.iucnredlist.org/details/37781/0
http://www.iucnredlist.org/details/195893/0
https://en.wikipedia.org/wiki/Tahina_spectabilis
http://www.iucnredlist.org/details/159126/0
https://en.wikipedia.org/wiki/Mammillaria_herrerae
http://www.iucnredlist.org/details/40838/0