When he returned to Athens on August 11, 1850, he was appointed Professor of Botany at the
National and Kapodistrian University of Athens. Four years later in 1854, he was awarded full Professor status. He maintained his position for over thirty years. The university was very political in nature. College professors usually participated in political debates and issues.
Dimitrios Stroumpos and
Ioannis Papadakis were some of the other professors dragged into Greece's political issues. The university faculty and government created an alliance that led to the departure of world-renowned astronomer
Georgios Konstantinos Vouris.
Vouris was Greek-Austrian. He was from the same country as the
King of Greece. During the years 1867 – 1868 Orphanides was Rector of the University. He was tirelessly collecting floral species from all over Greece. Theodore pressed the plants using a
plant press and prepared them for classification. Specimens were prepared and glued to archival-quality
card stock with their labels. Labels were made with special ink and attached with archival-quality glue. Theodore prepared countless plant specimens. The dried plants were added to his herbarium some were sent to botanists all over the world. His plant material formed a remarkable
Herbarium with over 45,000 specimens. He traveled across Greece studying plant diversity. He published his findings in an
exsiccata work entitled
Flora Graeca Exsiccata. Theodore was also the superintendent of the botanical garden and the state arboretum, he introduced ornamental plants and he was actively involved in the design and creation of urban public parks. He oversaw the creation of the
National Garden of Athens. Theodore frequently collaborated with world-renowned botanists some included
Theodor von Heldreich and
Pierre Edmond Boissier. When he died his
Herbarium was purchased by national benefactor
Theodoros Rodokanakis.
Rodokanakis donated the collection to the Botanical Museum of the University. After his death in 1886,
Theodor von Heldreich distributed an exsiccata-like specimen series under the title "Reliquiae Orphanideae curante Th. de Heldreich anno 188. emissae". ==Rectors Speech ==