XVII. CEDRELINGA DUCKE
Cedrelinga Ducke, Arch. Jard. Bot. Rio de Janeiro 3: 70. 1922. — Sp. typica: C. cateniformis (Ducke) Ducke = Piptadenia catenaeformis Ducke.
Cedrelinga is a monotypic genus without obvious close kindred in Ingeae, but seems most closely related to Albizia and Enterolobium sect. Enterolobium on the basis of the sylleptic, annual, axillary, strictly reproductive branches. Apart from its great stature, it may be known at anthesis by the unusual asymmetry of the ample, finely reticulate leaflets (the costa at once arched backward and postically displaced from midblade), by the terminal panicle of pseudoracemose capitula, and by corolla lobes separating downward as far as the stemonozone, therefore at maturity lacking a tube free from the androecium. The very large, papery lomentiform fruit twisted through about 90° at each interseminal isthmus is unique and unmistakable. The thin, exareolate, eventually fragile seed-testa suggests affinity with the Zygia group of Ingeae, but this hypothesis requires confirmation from seed morphology. Such anemochorous seeds could have evolved independently.
In his key to Mimosoideae of Brazilian Amazonia, Ducke (1949: 18) described the peduncles of Cedrelinga as arising from swollen nodosities resembling those bearing the individual flowers of many phaseoloid Fabaceae. The inflorescence nodes of Cedrelinga are indeed a trifle thickened under the serially bifarious peduncles, which are otherwise not different from those of other Ingeae, but the swelling is of course not homologous with those of Phaseoleae.
Cárdenas (1974: 124, 129) without explanation referred Cedrelinga to a comprehensive Pithecellobium of vast morphological diversity, but simultaneously maintained Enterolobium as a distinct genus. Such inequitable character-weighting seems capricious and inadmissible.