Rough Tree Fern (Dicksonia squarrosa)
Species: D. squarrosa
Binomial name: Dicksonia squarrosa
Common names: Rough tree fern, Wheki, Brown tree fern.
The New Zealand tree fern Dicksonia squarrosa is the most abundant medium-sized tree fern. It has a tall slender brown trunk. This fern produces few fronds, all of which sprout in almost horizontal fashion. The fronds reach 1.5 - 3 m in length, much smaller than Cyathea varieties, and are quite crisp to touch. They form a small "umbrella" on top of the trunk. It has a fast growth rate of up to 10 cm (5 in) a year, growing up to 6 m tall. The stipes are covered with longish brown black hairs. The upper part of the trunk can be covered with dead fronds. These ferns are sometimes found sprouting from apparently dead pieces of trunk. Since it often sends out underground rhizomes that produce new plants it is often found in colonies. The trunks are often used for fencing or edging and fronds will sometimes sprout from the side if top is dead.
Dicksonia squarrosa (adult ) middle Cyathea medullaris on right
Cyathea medullaris on left, Dicksonia squarrosa middle
Dicksonia squarrosa topside frond pinnae
Underside of Dicksonia squarrosa pinnae
The underside of a fertile frond showing sori.
(A sori is a cluster of sporangia (structures producing and containing spores)