Cecropia is a Neotropical genus consisting of 61 recognized species with a highly distinctive lineage of dioecious trees.[1]The genus consists of pioneer trees in the more or less humid parts of the Neotropics, with the majority of the species being myrmecophytic.[2] Berg and Rosselli state that the genus is characterized by some unusual traits: spathes fully enclosing the flower-bearing parts of the inflorescences until anthesis, patches of dense indumentums (trichilia) producing Mullerian (food) at the base of the petiole, and anthers becoming detached at anthesis.[2] Cecropia is most studied for its ecological role and association with ants.[2] Its classification is controversial; in the past, it has been placed in the Cecropiaceae, Moraceae (the mulberry family), or Urticaceae (the nettle family).[3] The modern Angiosperm Phylogeny Group system places the "cecropiacean" group in the Urticaceae.
The genus is native to the American tropics, where it is one of the most recognizable components of the rainforest. The genus is named after Cecrops I, the mythical first king of Athens. Common local names include yarumo or yagrumo, or more specifically yagrumo hembra ("female yagrumo") to distinguish them from the similar-looking but unrelated Didymopanax (which are called yagrumo macho, "male yagrumo"). In English, these trees are occasionally called pumpwoods (though this may also refer to C. schreberiana specifically) or simply Cecropias. Spanish-speaking countries in Central America, Mexico, the Caribbean, Colombia, and Ecuador commonly use the vernacular name, guarumo.[2]
Cecropia was first recognized and accounted for by Marcgrave (1648) and Piso (1658), the latter including an illustration with characteristic features.[2] Loefling (1758) coined the generic name Cecropia.[2] In 1759, Linnaeus described Cecropia peltata which he applied to many species.[2] Willdenow (1806) created C. palmate, which was also applied to a various species.[2] Over the next decade, additional species were added by Bertoloni (1840), Martius (1841), and Liebmann (1851).[2] Mixing of specimens was very common and a problem arose, which continues today, with many collections of Cecropia. Many species were also described by Hemsley (1883), Richter (1897), Donnell Smith (1899), Rusby (1907, 1910), Huber (1910), Robinson (1912), Pittier (1917), Bailey (1922), and the most extensive number by Snethlage (1923, 1924).[2] Additional species were recognized by Burret (1924), Mildbread (1925, 1933), Standly (1929, 1940), Macbride (1937), Diels (1941), Standley & Steyermark (1944), and Stadley & Williems (1952).[2]
Hans Melchior (1964) placed Cecropia in the Urticales and Moraceae (Concephaleideae) because of its woody bark.[4] Later based on the floral characters, most notably the basal ovule and gynoecium, which appears to be formed from a single carpel, Thorne (1976) moved it to the Malvanae- Urticales, family Urticaceae.[5] Berg (1978), however, placed it in its own family Cecropiaceae. When phylogenetic data became available, Cecropia was then moved back into the Urticaceae.[6]