Martinique has 259 species of pteridophytes (i.e ferns and allied plants), of which 247 are native. They can be herbaceous, aquatic, and even arboreal or ligneous in humid forests. These vascular plants with leaves called fronds do not have flowers nor seeds and proliferate exclusively through spores. Their spores need water to ensure their reproductive function, which explains the presence of ferns in humid places (hygrophilous forests, rivers) and their absence from the driest areas.