Catkin Walk

The February 11, 2009 Walk and Learn for the Friends of the Garden was on the topic of catkins. These are some of the plants we encountered and ideas we discussed:

Food Garden

• Corylus avellana (common hazelnut or common filbert) -- long pendulous pale yellow male catkins and shorter female catkins with small red nodule on the stem above the catkin. Shed pollen in December and January in Vancouver. Protective measure ensures complete pollen distribution by gradual catkin development on each tree. Wind pollinated.

Native Garden

• Alnus rubra (red alder) -- Catkins develop on bare branches in late winter. Male catkins elongate to about 5 to 10 cm and become dull yellow as they shed pollen in March. Small female catkins are in clusters of 3 to 5 become hard and woody resembling a small conifer cone. Wind pollinated.
• Myrica californica (California wax myrtle) -- Evergreen leaves have black dots. No catkins at this date.
• Myrica gale (sweet gale) -- Deciduous leaves have yellow dots. This is an important nitrogen fixing species.
• Betula papyrifera (white birch, canoe birch) -- Male and female flowers in separate catkins 2 to 4 cm long. Flower at same time before leaves emerge.

Alpine Garden

• Salix gracilistyla 'Melanostachys' (black pussy willow) -- Deciduous. Black catkins with red anthers in early spring before leaves. Dioecious. Insect pollinated.
• Nothofagus antarctica (Antarctic beech) -- no catkins at this date.
• Garrya elliptica (or similar) (silk tassel bush) -- long gray-green male catkins

Discussion on convergent evolution: the process whereby organisms that are not closely related, evolve similar traits as a result of having to adapt to similar environments. A good example of this is the catkin and the cone.