Sunday, August 28, 2016

Day trip to the coast: a palm, an orchid, and a fern

Today I joined an ANU biology professor and his partner on a day trip to the coast. We saw a bunch of nice plants, and coming back I was able to show my daughter some cool cryptogams under the microscope mentioned in a previous post.

The view of the ocean from the escarpment. The dark tree in the centre was actually the occasion for this trip, as we wanted to find out what it was.

Livistona australis (Arecaceae), the most common palm in this area. I just like how this photo came out.

In a nearby swamp Dockrillia teretifolia (Orchidaceae) was just now in flower. This beautiful orchid grows pretty much only epiphytically on the trunks of Casuarinaceae. The flowers have a sweet, honey-like scent.

On some rocks in a moist, shady place I found carpets of this filmy fern (Hymenophyllaceae). I was particularly happy to find it fertile; note how the sporangia are poking out of the little pockets formed by two lobes. This photo may come in handy if I ever give a talk about ferns.

Because filmy fern leaves are reduced to only one cell layer - these are, in a sense, ferns that want to become liverworts - I thought it would be nice to take a bit home and examine it under the aforementioned microscope. But even I was surprised at how large the cells are and how much one can see. This makes me really happy; my daughter has seen chloroplasts at age seven!

Then she continued to take more pictures on her own initiative and got this nice snapshot of the sporangia. Yes, they are on top of each other, and the spores are not visible, but the annulus typical of leptosporangiate ferns came out really nicely. This row of cells with U-shaped wall thickenings tears open the sporangium at maturity to release the spores.

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