How do cycad seeds germinate?

Cycad seeds do not undergo a dormant period or require after-ripening, which is a departure from the typical dormancy seen in many other gymnosperms and angiosperms. In some instances, cycad seeds may even begin the germination process while still attached to the parent plant's sporophylls.12

The germination process is characterized by the following:

• Inhibitors: The outer fleshy layer of the seed may contain germination inhibitors; consequently, removing this layer or using scarifying agents can often accelerate the process.1
• Nutritional Dependence: Once germination begins, the embryo remains attached to the female gametophyte for up to two years. During this time, it absorbs essential nutrients through its cotyledons, which stay embedded within the gametophyte.1
• Root Development: The seedling quickly develops a fleshy taproot to support its growth.1

Because cycad seeds are heavy and often lack effective natural dispersal mechanisms, many germinate at the base of the parent plant, where they may struggle to survive.1