Blood orange

Citrus sinensis – Malta Orange

In 19th-century Paris, fruit sellers distinguished two main families of oranges: those with red flesh, known as Malta oranges, and those with yellow flesh, called Portugal oranges.

Yet, behind this convenient classification lay unsuspected diversity. Poiteau keenly observed that round and oblong fruits, with yellow and red flesh, could grow on the same Portuguese orange tree. Even more extraordinarily, as reported in February 1830, an orange was found with one quarter displaying the characteristics of a citron. This variability, a source of astonishment for botanists of the time, attests to the remarkable plasticity of citrus fruits and the mystery that still surrounded their reproduction.

The Malta orange is distinguished by its vinous red flesh, its thin, uniform, and shiny skin; criteria for the best quality according to Parisian market sellers.

Poiteau notes a fascinating botanical peculiarity: contrary to Gallesio's assertion, these red oranges contained numerous perfectly formed seeds, some harboring up to four or five embryos under the same integument, a phenomenon then poorly understood, now explained by polyembryony, which is more common in orange trees than in any other plant family.

The author also notes an astonishing behavior: fruits left on the tree after December lose their juice in spring during sap rise, then refill in autumn to become "better than the first time," a living illustration of the balance of plant fluids.

This plate is taken from Pierre-Antoine Poiteau and Pierre Jean François Turpin's Traité des Arbres Fruitiers (Treatise on Fruit Trees), a fruit encyclopedia published between 1807 and 1835, a major reference in 19th-century naturalist illustration.

It combines the rigor of scientific drawing with a rare artistic sensibility, characteristic of the great plates of the golden age of illustrated botany.