Which best describes the earliest land plants?
The earliest land plants, also known as embryophytes, were small and simple,
lacking the complexity of their modern counterparts. These plants did not have
true roots, stems or leaves, but rather simple structures that absorbed
nutrients from the surrounding soil and air. Early land plants had a symbiotic
relationship with fungi that helped them absorb nutrients from the soil, and
some plants developed specialized structures, like rhizoids, to anchor
themselves to the ground.
The first land plants were thought to have evolved from green algae and
appeared around 500 million years ago during the Ordovician period. The
earliest known land plant fossils are from liverworts, mosses, and hornworts,
which are still found today in diverse ecosystems around the world. These
early plants were critical to the evolution of life on land as they paved the way
for the development of more complex plant forms and contributed to the
creation of fertile soils necessary for other life forms to thrive.
References:
- Kenrick, Paul, and Peter R. Crane. The Origin and Early Diversification of Land Plants: A
Cladistic Study. Smithsonian Institution Press, 1997.
- Edwards, Dianne, et al. "The Evolutionary History of the Seed Plant Flora: Fossils,
Phylogenies, and Divergence Times." Critical Reviews in Plant Sciences, vol. 35, no. 5-6,
2016, pp. 235-292.
- "The Plant Kingdom." Biology LibreTexts, University of California, 2019,
bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_General_Biolo
gy_(Boundless)/25%3A_Plant_Form_and_Function/25.3%3A_The_Plant_Kingdom/25.3B%
3A_The_Evolution_of_Plants_on_Land .