National Arbor Day in Venezuela is celebrated on the last Sunday in May. This holiday, which focuses on planting and caring for trees, has its origins in a decree by President Cipriano Castro on April 10, 1905, when it was initially observed on May 23. The observance was later moved to May 15 in 1909 and then to May 29 in 1948 to honor the araguaney (Tebebuia crysantha), declared the National Tree of Venezuela due to its emblematic status and beautiful yellow flowers resembling the national flag. Since 1951, the holiday has been consistently held on the last Sunday in May, encouraging Venezuelans to plant trees and contribute to the preservation of the country's rich flora, which includes around 38% of its estimated 21,000 plant species being endemic.