Difference Between Bryophytes and Seedless Vascular Plants

The key difference between bryophytes and seedless vascular plants is that bryophytes are non-vascular plants, while seedless vascular plants are vascular plants that do not produce seeds.

Kingdom Plantae is the kingdom that consists of all plants on Earth. Plants are multicellular eukaryotes which are photoautotrophic. Based on the plant body, vascular tissues and seed developments, plants can be further categorized into five subgroups as Thallophyta, Bryophyta, Pteridophyta, gymnosperms and angiosperms. Bryophytes are small plants growing in moist and shady places. They originate in both land and aquatic environments. Bryophytes lack true vascular tissues to conduct water and nutrients. Therefore, bryophytes are non-vascular plants. Pteridophyta contains vascular plants which do not produce seeds, fruits and flowers. They are also known as seedless vascular plants. Ferns and horsetails are two major groups of seedless vascular plants. Both bryophytes and seedless vascular plants are primitive plants which reproduce via spores.

CONTENTS

1. Overview and Key Difference
2. What are Bryophytes 
3. What are Seedless Vascular Plants
4. Similarities Between Bryophytes and Seedless Vascular Plants
5. Side by Side Comparison – Bryophytes vs Seedless Vascular Plants in Tabular Form
6. Summary

What are Bryophytes?

Bryophytes are the most primitive type of plants in nature. They live in moist environments. They show alternation of generations. The gametophytic generation of bryophytes is dominant. The gametophyte is independent and haploid. It consists of a small stem with leaf-like projections termed as pseudo leaves or leafless flattened bodies. Bryophytes anchor to surface through thread-like structures called rhizoids. The gametophyte reproduces sexually, giving rise to a diploid sporophyte. The sporophyte is dependent on the gametophyte.

Bryophytes depend on water for fertilization. They usually depend on a film of water or splashing of raindrops for transfer of sperms to the egg. Bryophytes produce motile flagellate sperms which are directed to the archegonium. The fertilized egg (zygote) grows out of the gametophyte.

What are Seedless Vascular Plants?

Seedless vascular plants are the first terrestrial vascular plants which include ferns, horsetails, etc. They belong to subgroup Pteridophyta. These plants do not produce seeds, fruits and flowers. They produce spores in order to reproduce. Though seedless vascular plants are primitive plants, they do have true stems, roots and leaves. Hence, their plant body is a differentiated body. Moreover, they have true vascular tissues, unlike bryophytes. However, in seedless vascular plants, vessel elements in xylem tissue and sieve tube elements and companion cells in phloem tissue are absent. The leaves contain a prominent cuticle and stomata, and they are arranged as compound leaves, and the arrangement is referred to as a frond arrangement. The young leaves show circinate vernation. Circinate vernation is a unique feature of seedless vascular plants.

Since seedless vascular plants are primitive plants, they depend on water for fertilization. Hence, they live in wet, moist and shady environments. Furthermore, seedless vascular plants show alternation of generation. Their dominant generation is sporophytic generation. The gametophyte is a prothallus, which is a flat, heart-shaped independent structure. It is photosynthetic and monoecious (antheridia and archegonia are in the same structure). Archegonium is the female structure that produces ova. Antheridium is the male structure that produces multi-flagellated sperms. After fertilization, the zygote develops into an embryo and into the sporophyte.

Seedless vascular plants, especially ferns, are grown as ornamental plants in domestic environments. They are also useful as medicines, biofertilizers and remediating contaminated soils.

What are the Similarities Between Bryophytes and Seedless Vascular Plants?

• Bryophytes and seedless vascular plants are two major groups of plants that are multicellular eukaryotes.
• Both are primitive plants.
• They do not produce seeds, flowers or fruits.
• They are spore-producing plants.
• Also, both show alternation of generation.
• Besides, they depend on water for fertilization, so both plants need moist environments to live.

What is the Difference Between Bryophytes and Seedless Vascular Plants?

Bryophytes are a subgroup of plants that includes non-vascular small plants growing in moist shady places. In contrast, seedless vascular plants are the group of plants that are considered as the first true terrestrial vascular plants. So, this is the key difference between bryophytes and seedless vascular plants. Vascular tissues are absent in bryophytes while seedless vascular plants have true vascular tissues. However, both groups show alternation of generation. Gametophytes are dominant in bryophytes, while sporophytes are dominant in seedless vascular plants. Thus, this is also a difference between bryophytes and seedless vascular plants.

Moreover, bryophytes lack true roots, stems and leaves while seedless vascular plants have true stem, roots and leaves. Mosses, hornworts and liverworts are bryophytes while ferns, horsetails, Marsilea, etc. are seedless vascular plants.

Below infographic tabulates the differences between bryophytes and seedless vascular plants for side by side comparison.

Summary – Bryophytes vs Seedless Vascular Plants

Bryophytes are the most primitive plants and include mosses, liverworts and hornworts. They do not possess a true vascular tissue system. They grow in damp environments. Seedless vascular plants, on the other hand, are the first true terrestrial vascular plants. They are primitive plants that do not produce seeds, fruits and flowers. They reproduce via spores. They depend on water for fertilization; hence they grow in moist environments. Both bryophytes and seedless vascular plants are primitive plants. Both show alternation of generations. But, in bryophytes, the gametophyte is dominant while in seedless vascular plants, the sporophyte is dominant. Moreover, bryophytes lack true stem, roots and leaves while seedless vascular plants have true stem, roots and leaves. Thus, this summarizes the difference between bryophytes and seedless vascular plants.

Reference:

1. “Bryophytes.” Northern Virginia Community College | Biology II, Available here.
2. “Seedless Vascular Plants.” Lumen, Available here.

Image Courtesy:

1. “Mousse Bryophytes. Mahieddine Boumendjel” By Mahieddine Boumendjel – Own work (CC BY-SA 3.0) via Commons Wikimedia

2. “5135775” (CC0) via Pixabay