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Article: The question of cotyledon homology in angiosperms.
- Article from:
- The Botanical Review
- Article date:
- October 1, 1998
- Author:
CopyrightCOPYRIGHT 1998 New York Botanical Garden. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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II. Introduction
The most fundamental difference between monocotyledons (monocots, Liliopsida) and dicotyledons (dicots, Magnoliopsida) expresses itself early in the ontogeny of the plant body, as the contrasting names of these great lineages imply. During early embryogenesis, from the quadrant and octant stages up to the globular proembryo [ILLUSTRATION FOR FIGURE 1A OMITTED], there is no significant difference between monocots and dicots (Natesh & Rau, 1984). Soon after a globular stage is formed, the developmental trajectory of the embryo takes one of two paths. In dicots a "heart-shaped" structure is precursor to two cotyledons flanking a central depression ...