2. Fruit in a club-shaped, brown or cinnamon-colored spike loaded with
sporangia; fruit in early spring.

Cinnamon Fern. _Osmunda cinnamomea_.

[Illustration]

3. Fruit in berry-like, greenish structures in a twice pinnate spike, which
comes up much later than the broad and coarse pinnátifid sterile fronds.

Wet ground. Sensitive Fern. _Onoclea_.

[Illustration]

4. Fruit in pod-like or necklace-like pinnæ; fertile frond pinnate; sterile
frond tall, pinnátifid; fruit late.

Ostrich Fern. _Onoclea struthiopteris_.


B. FRUITING FRONDS PARTLY STERILE

[Illustration]

1. Fruiting portion in the middle of the frond; two to four pairs of
fertile pinnæ.

Interrupted Fern. _Osmunda Claytoniana_.