Lycophyte

A vascular plant in the lineage that includes clubmosses, spike mosses, and quillworts. Lycophytes are distinguished by small leaves with a single unbranched vein.

Microphyll: A small leaf with a single unbranched vascular strand. Microphylls are the characteristic leaves of living lycophytes.
Heterospory: The production of two distinct spore types: microspores and megaspores. Some lycophytes separate male and female gametophyte development through different spores.
Clubmoss: A spore-producing lycophyte with branching shoots and small scale-like leaves. Clubmosses are familiar living members of the lycophyte lineage.
Cooksonia: An extinct early vascular plant with slender branching stems and terminal sporangia. It illustrates the simple body plans among the earliest known vascular plants.
Monilophyte: A vascular plant in the lineage that includes ferns and horsetails. Monilophytes are the other major living lineage of seedless vascular plants.
Vascular plant: A plant with specialized tissues that transport water, minerals, and sugars. Lycophytes belong to the vascular plants, alongside ferns and seed plants.
Homosporous plant: A plant that produces spores of one size and type. Many lycophytes contrast with heterosporous relatives by producing one spore type.
Spike moss: A lycophyte in the genus Selaginella, often with flattened, branching shoots. Spike mosses exemplify the diversity of living lycophyte growth forms.
Silurian: A geologic period spanning about 443.8 to 419.2 million years ago. Early lycophyte relatives appear in the fossil record during this period.
Euphyllophyte: A vascular plant in the lineage that includes ferns, horsetails, and seed plants. Lycophytes diverged from the lineage leading to euphyllophytes.

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