Powell's specimen records (also known as herbarium specimens) and his Panama garden were studied by researchers at the Royal Botanical Gardens, the Berlin Botanical Garden, the Orchid Herbarium of Oakes Ames at Harvard University, the National Museum of Natural History at the Smithsonian Institution, and the Missouri Botanical Garden (MBG). Dozens of orchid species were named in his honor. In 1922, German botanist Rudolf Schlechter published his 95-page Orchidaceae Powellianae Panamenses (Panama orchid collections by C. Powell): principally on the basis of Powell's efforts. Powell's work remains relevant not only because his records document valuable scientific data, but they continue to provide material for study – many of his digitized herbarium specimens are freely available online via virtual herbaria.
In 1926, Powell donated his world-class orchid garden (orchidarium) to the renowned MBG of St. Louis, Missouri. Under Powell's direction, a Tropical Station was created by the MBG in Balboa, Panama; 7,000 plants from Powell's orchid garden populated the satellite operation. For the MBG, a snowball effect occurred in the tropics; orchid collecting began there in earnest and over the next 13 years, orchids from its Tropical Station would appreciably augment the collection of the parent garden in St. Louis. "Today, the Missouri Botanical Garden’s orchid collection represents one of the largest and finest in the United States."
Known to orchid enthusiasts as C. W. Powell, he was born Charles Lesslie Pullen in Richmond, Virginia, to Benjamin King Pullen Sr. and Minerva "Minnie" Anner (née Smith) Pullen. He was the first-born of eight children. In a letter to Minnie dated July 29, 1854, from Richmond, Ben Pullen writes about his son:
In 1860, 6 year old Lesslie and his family moved, by train, 800 miles (1,300 km) southwest to Memphis, Tennessee, for the opening of his father's china store. Shortly thereafter, Lesslie was uprooted again when his family relocated 50 miles (80 km) south for several years. There they struggled to survive on a cousin’s farm near Sardis, Mississippi, during the Union Army's occupation of Memphis in the American Civil War and Ben Pullen Sr.'s service as a Confederate Army officer. Perhaps this experience was Lesslie's introduction to agriculture.
After the War, the Pullens moved back to Memphis. In 1871, hard times in the South forced Lesslie’s father to advertise his store's closing. By the mid-1870s, Ben Pullen Sr. was a bookkeeper for the State National Bank and Lesslie, now calling himself Charles, was a collector for the bank.