Overview
The Palma Corcho (Microcycas calocoma) is a legendary living fossil and the sole member of its endemic monotypic genus, restricted strictly to the dramatic limestone mogote landscapes of western Cuba. Despite its vernacular Spanish name translating to ‘cork palm,’ it is not a palm but an ancient arborescent gymnosperm whose lineage has remained largely unchanged since the Jurassic period, declared a National Monument of Cuba to safeguard its final remnants.
Biology and Physical Characteristics
Attaining a stately height of up to 30 feet, Microcycas calocoma produces an erect, columnar fibrous trunk with soft, corky bark from which its common name is derived. The trunk is crowned by a dense, spherical rosette of graceful, arched fronds with blunt-tipped, light-green leaflets that droop gracefully at the ends, giving the crown a distinctive shaggy, umbrella-like appearance. Remarkable among all seeded plants, male plants produce huge pollen cones that generate the largest flagellated spermatozoids known in the botanical world, each swimming with thousands of microscopic cilia.
Behavior and Ecology
Microcycas calocoma thrives in poor, shallow soils clinging directly to vertical limestone cliffs and karst pockets. It forms specialized coralloid roots near the soil surface housing symbiotic Nostoc cyanobacteria that convert atmospheric nitrogen into usable plant nutrients. Pollination is performed primarily by a specialized obligate weevil (Pharaxonotha species) that lives exclusively inside the reproductive cones, carrying pollen grains from male cones to ovule-bearing female cones in an ancient mutualistic partnership.
Conservation and Human Impact
Ranked as Critically Endangered by the IUCN, fewer than 600 wild individuals survive across fragmented populations in Pinar del Río. Historically cleared for tobacco cultivation, coffee plantations, and timber, the remaining colonies suffer from extremely low natural recruitment due to pesticide use that decimated its obligate weevil pollinators. Cuban botanists and national park authorities now conduct hand-pollination programs and protected habitat management within Viñales National Park.
Interesting Factoid
Microcycas calocoma produces the largest swimming sperm cells of any plant on Earth—microscopic botanical swimmers equipped with over 40,000 tiny thrashing cilia to fertilize the female ovule!
Last updated: October 2026