Cycas micronesica, commonly known as the Micronesian cycad, Federico palm, or fadang in Chamorro, is a species of ancient, palm-like gymnosperm belonging to the family Cycadaceae. Native to the Mariana Islands (including Guam and the Commonwealth of the Northern Mariana Islands), as well as parts of Palau and the Yap islands in Micronesia, it is the only native gymnosperm tree species in its natural island range. The genus name Cycas derives from the ancient Greek word koikas, meaning a kind of palm, while the species epithet micronesica refers to its native geographic distribution across the Micronesian region. Historically, Cycas micronesica held immense ecological and cultural significance, most notably serving as a critical famine food and a staple carbohydrate source for the indigenous Chamorro people of Guam, despite requiring intensive, multi-step processing to remove potent native toxins.

The plant features a stout, woody, unbranched trunk that can grow up to 12 meters in height, topped by a striking crown of large, stiff, glossy green pinnate leaves (fronds) that emerge in symmetrical flushes. Like all cycads, Cycas micronesica is dioecious, meaning individual plants bear either male cones or female reproductive structures. Female trees produce large, woolly megasporophylls that hold clusters of large, ovoid seeds covered in a fleshy, bright orange or yellow outer sarcotesta. The species is remarkably resilient, capable of surviving coastal salt spray and severe typhoons, though in recent decades wild populations have faced severe decline due to invasive insect pests, particularly the Asian cycad scale (Aulacaspis yasumatsui) and the cycad blue butterfly.

In culinary and cultural traditions, particularly within Chamorro heritage, the seeds of Cycas micronesica are the primary source of edible starch, traditionally known as fadang flour. However, raw or improperly prepared cycad seeds are intensely poisonous, containing dangerous neurotoxins and carcinogenic compounds. To render the starchy kernels safe for human consumption, traditional preparation requires a rigorous, multi-day process of shelling, slicing, prolonged soaking in running water, and repeated washing to leach out water-soluble toxins before the remaining material is dried and ground into flour for use in traditional porridges, tortillas, and baked dishes.

From a toxicological and pharmacological perspective, Cycas micronesica is heavily studied for its unique and potent secondary metabolites. The plant contains two primary classes of toxins: cycasin (a toxic glycoside that breaks down into carcinogenic methylazoxymethanol) and BMAA (beta-N-methylamino-L-alanine, a neurotoxic non-protein amino acid). Epidemiological research has historically investigated the presence of BMAA in traditional food chains—mediated through flying foxes that feed on cycad seeds—as a potential environmental trigger contributing to high historical rates of neurodegenerative conditions such as Lytico-Bodig disease (a cluster of amyotrophic lateral sclerosis, parkinsonism, and dementia) among the indigenous population of Guam.