Apocynaceae wood evolution matches key morphological innovations.

Area of Science:

• Plant anatomy
• Evolutionary biology
• Systematics

Background:

• The dogbane family (Apocynaceae) exhibits diverse wood anatomy, growth forms, and floral structures.
• Understanding the evolution of these traits is crucial for phylogenetic and ecological studies.

Purpose of the Study:

• To provide an overview of Apocynaceae wood anatomy.
• To reconstruct the evolutionary history of wood anatomical traits.
• To link wood anatomy evolution with growth-form transitions and floral/seed trait innovations.

Main Methods:

• Revision of over 200 published wood anatomical descriptions.
• Microscopic analysis of wood sections from 50 additional species.
• Ancestral state reconstructions and correlated evolution tests using anatomical and floral/seed traits.

Main Results:

• A distinct suite of wood anatomical traits (e.g., vessel multiples, laticifers, vascular cambial variants) characterizes core apocynoids.
• This trait suite correlates with floral morphological innovations and transitions to climbing or herbaceous habits.
• Shortening of vessel elements and fibers is linked to reduced plant size.

Conclusions:

• Evolutionary shifts in wood anatomy represent structural adaptations within Apocynaceae.
• These adaptations are associated with rapid evolutionary changes in the floral body plan (bauplan).