Some plants reproduce with spores rather than seeds. We will also examine the broader classification system for all living organisms.
Basic Knowledge
Plants that do not produce seeds:
① Ferns (Pteridophytes): Have vascular bundles, distinct roots, stems, and leaves, and reproduce by spores. Examples: Japanese climbing fern, royal fern, horsetail, and bracken
② Mosses (Bryophytes): Have no vascular bundles, do not have clearly distinct roots, stems, and leaves, reproduce by spores, and use rhizoids to anchor their bodies. Examples: liverworts and hair-cap mosses
Spores are produced in sporangia (in ferns, they gather on the underside of leaves as sori), dispersed by wind, and develop into new individuals.
Hierarchy of the plant kingdom:
Plant kingdom → (seed plants: angiosperms and gymnosperms / non-seed-producing plants: ferns and mosses)
More broadly, the entire living world can be divided by systems such as the five-kingdom system into plants, animals, fungi, protists, and prokaryotes.
Ferns (Pteridophytes)（Have vascular bundles and reproduce by spores. Japanese climbing fern and horsetail）
Mosses (Bryophytes)（No vascular bundles and have rhizoids. Liverworts and hair-cap mosses）
Spore (spore)（A reproductive cell that takes the place of a seed. One cell）
Sporangium (sporangium)（A sac-like organ that produces spores）
Rhizoid (rhizoid)（A hair-like structure that mosses use to anchor themselves. It does not absorb water）
Taxonomic ranks（Kingdom → phylum → class → order → family → genus → species）
Further Study (Background and Significance)
In evolutionary order: mosses → ferns → gymnosperms → angiosperms. Mosses are closely related to the ancestors of plants that first colonized land, about 470 million years ago. Ferns became enormous during the Carboniferous Period (about 300 million years ago) and became the raw material for coal.
Because mosses do not have vascular bundles, they absorb water directly through their entire bodies. Therefore, they are vulnerable to drying and are commonly found in damp places. Rhizoids are not “replacement roots”; their main function is simply to anchor the body to the ground.
The taxonomic ranks (kingdom, phylum, class, order, family, genus, and species) were proposed by Linnaeus in the 18th century and remain fundamental to biology. Scientific names of species are written using binomial nomenclature (genus name + specific epithet); humans are Homo sapiens.
In recent years, the three-domain system (Bacteria, Archaea, and Eukarya) has become standard with advances in molecular biology and is widely accepted as a classification above the five-kingdom system.
- Non-seed-producing plants = ferns and mosses
- Ferns = have vascular bundles and sori on the undersides of leaves
- Mosses = no vascular bundles and are anchored by rhizoids
- They reproduce by spores, not seeds
- Plant evolutionary order: mosses → ferns → gymnosperms → angiosperms
- Taxonomic ranks: kingdom, phylum, class, order, family, genus, species
- Binomial nomenclature: genus name + specific epithet (italicized)
Points to Note (Easily Confused)
① Ferns have vascular bundles, while mosses do not. Be careful because this is easy to confuse. ② Moss rhizoids do not absorb water; they are used only for anchoring. ③ A spore is one cell, whereas a seed is a complex structure containing an embryo, endosperm, and seed coat. They are different. ④ The decisive difference between “ferns and mosses” and “gymnosperms and angiosperms” is whether they produce seeds.
Practice
- Do mosses have vascular bundles?
- What is the cluster of sporangia found on the underside of fern leaves called?
- Arrange “mosses, ferns, angiosperms, gymnosperms” in the correct evolutionary order.