Core eudicots

Core Eudicots

The core eudicots are a large clade of flowering plants that form a major part of the angiosperms. They are distinguished from other eudicots by certain genetic and morphological characteristics. This group includes many of the most familiar plants, such as roses, sunflowers, and oaks.

Characteristics

Core eudicots are characterized by a number of features that distinguish them from other plant groups. These include:

• Tricolpate pollen: The pollen grains typically have three apertures or furrows.
• Distinctive floral structures: Many core eudicots have flowers with a specific arrangement of petals, sepals, and reproductive organs.
• Genetic markers: Molecular phylogenetic studies have identified specific genetic sequences that are characteristic of core eudicots.

Major Groups

The core eudicots are divided into several major groups, each containing numerous families and species. Some of the most significant groups include:

Rosids

The Rosids are a large clade within the core eudicots, comprising about 70,000 species. They are further divided into two major groups:

• Fabids: This group includes the legume family (Fabaceae), which is economically important for its nitrogen-fixing ability.
• Malvids: This group includes the mustard family (Brassicaceae), known for species like cabbage and mustard.

Asterids

The Asterids are another major clade within the core eudicots, with about 80,000 species. They are characterized by:

• Sympetalous flowers: Flowers with fused petals.
• Iridoid compounds: Chemical compounds that are often found in this group.

Evolution and Phylogeny

The core eudicots are believed to have diverged from other eudicots approximately 125 million years ago during the early Cretaceous period. Phylogenetic studies using DNA sequencing have helped clarify the relationships within this group, revealing a complex history of diversification.

Economic Importance

Core eudicots include many plants of significant economic importance. Some examples are:

• Food crops: Many fruits, vegetables, and grains come from core eudicots, such as apples, tomatoes, and wheat.
• Medicinal plants: Numerous medicinal plants, including those used in traditional and modern medicine, belong to this group.
• Ornamental plants: Many popular garden plants, such as roses and sunflowers, are core eudicots.

Conservation

As with many plant groups, core eudicots face threats from habitat loss, climate change, and overexploitation. Conservation efforts are important to preserve the biodiversity and ecological roles of these plants.

References

• Angiosperm Phylogeny Group (APG). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV." Botanical Journal of the Linnean Society, 2016.
• Soltis, D. E., et al. "The origin and early evolution of angiosperms." Annals of the Missouri Botanical Garden, 2004.