In 2018 the United Nations Postal Administration issued a beautifully-illustrated set of stamps to celebrate 25 years of its Endangered Species series featuring 12 threatened flora and fauna species.
The €0.80 U.N. Vienna stamps here above show the leafless fat-stemmed succulent plant Hoodia (Hoodia pilifera); a frog native to Madagascar, the Malagasy painted Mantella (Mantella madagascariensis); an Assam roofed turtle (Pangshura sylhetensis) found in parts of India and Bangladesh; and a zebra seahorse (Hippocampus zebra), found only in waters near Australia.
The four $1.15 stamps for use from the U.N. New York stamps feature the attractive red-crested Turaco (Tauraco erythrolophus), a fruit-eating bird found in western Angola; the Andean hairy armadillo (Chaetophractus nationi), an armadillo native to Bolivia and northern Chile; a Luristan newt (Neurergus kaiseri), a salamander from the southern Zagros Mountain region in Iran; and the Goldenseal (Hydrastis canadensis), a perennial herb native to southeastern Canada and the eastern United States.
The CHF 1.50 U.N. Geneva stamps depict the Saiga antelope (Saiga tatarica), found on the open dry steppe grasslands and semi-arid deserts of central Asia; the succulent sesame (Uncarina grandidieri), a bright-yellow flower from Madagascar; the striking Cuban land snail (Polymita picta); and the silky shark (Carcharhinus falciformis), named for its smooth skin.