Parts of a fern

Dr Patrick Brownsey from Te Papa shows us the 3 major parts of a fern: the rhizome (the underground stem), the leafy frond and the sporangia (the reproductive structure).

Points of interest:

• What are the 2 functions of a fern frond?

• For more in-depth coverage of fern structure, visit the Fern structure and Underlay of a fern interactives.

Transcript

DR PATRICK BROWNSEY

There’s basically 3 major parts to the fern. There’s the rhizome, which is the underground stem of the fern, and then there’s these fronds here, and then when we turn the fronds over, there’s these brown structures on the underside, which are the sporangia, the reproductive structures.

So the rhizome here is, as I say, the underground stem, and it comes in basically 3 different forms. There’s just a short erect rhizome giving rise to a tuft of fronds, but other rhizomes can be creeping or they can be growing vertically to form a trunk as on tree fern trunks.

 Now the leafy part of the fern is what we’ve got here, but these are not entirely the same as a flowering plant leaf, because these fronds have a dual purpose. They are both photosynthetic, they’re green, so they produce energy from the chlorophyll there, but they are also reproductive, and when you see on the underside these brown lines that run along the veins are the sporangia, and they are little capsules that contain spores. And when they dry out, break open and they release the spores, which are dispersed into the air and germinate to form the gametophyte.

Acknowledgement:
Museum of New Zealand Te Papa Tongarewa