- botany the relatively small type of leaf produced by club mosses and horsetailsCompare megaphyll
- A leaf with only one vascular bundle and no complex network of veins. Horsetails and lycophytes (such as club mosses) have microphylls. Microphylls on modern plants are generally small but in extinct phyla the same structures could grow quite large. In contrast to megaphylls, microphylls are thought to have evolved from modifications of a single stem.
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