Moon snails' mysterious egg cases

Not showy but black grass has subtle beauty

Posted Jun 12, 2018 at 2:04 PM

Updated Jun 19, 2018 at 9:36 AM

I love close-up photography. A modern digital camera is like having a field microscope at your disposal. With everything growing so profusely right now it is a good time to get outside with a camera and stalk the small stuff. My recent goal was to find and photograph the tiny flowers of our local grasses.

When I used to work at the Wells National Estuarine Research Reserve one of the first things I learned about was zonation in a salt marsh. Different grasses grow at different elevations - cord grass grows low, down at the edge of the little tidal streams with its roots almost constantly submerged in water. Salt marsh hay grows a little further up on the broad expanses of the high marsh, generally submerged only at the monthly spring tides. Higher still, at the upper edge of the high marsh, black grass (Juncus gerardii) grows.

The road near my house cuts through a salt marsh. Right now, all along the edge of the road, which is the high tide line (the road floods whenever we get a spring tide), black grass is blooming - tiny green stalks topped with inconspicuous, dark, flower buds (inflorescences) that get tossed about in the breeze. I had never looked at these up close, but had a hunch that a close-up of that flower bud with my camera zoomed in would yield something wonderful - I wasn’t disappointed. Up close those non-descript capsules on the ends of the stems opened up into tiny Seussian flowers - ridiculously long sticky pink female stigmas surrounded by creamy yellow male anthers. I brushed some of the flower heads and large amounts of pollen billowed up into the air. That abundance of pollen is what those sticky pink stigmas are for -- to catch the pollen released by black grass flowers for fertilization of the egg (the stigma lies at the top of the female part of the plant - the carpel which is composed of the stigma resting on top of the tube-like style that leads down to the ovary).

Black grass isn’t actually a grass, it is in the rush family - plants we routinely lump in with the grasses but that are, in fact, a completely different family. You’ll find a combination of grasses, sedges (another grass-like plant) and rushes in most marshes. At one point I thought I would try to become an expert on identifying the different grasses, sedges and rushes. I thought it would be easy - turns out it isn’t. There are tons of grasses, sedges and rushes that all look remarkably similar to the untrained and require more than just a guide book to identify - in particular a huge, specialized vocabulary. However, distinguishing sedges from rushes from grasses is fairly straightforward. We used to teach a rhyme at the Wells Reserve that deals with this: “Sedges have edges, rushes are round, and grasses are hollow right down to the ground.” Here’s how this works -- find something that is grass-like and examine its stem. If it is hollow it is a grass. You can tell just be feel - it’ll feel squishy and can be somewhat flattened compared with the solid stem of a rush. Rushes feel rounder than grasses because they aren’t hollow. Sedges, on the other hand, have triangular stems, you can feel the edges if you roll the stem between your fingers. This rule doesn’t work for all grasses, sedges and rushes, but it is a good place to start. Grasses also have nodes along the stem (think bamboo), whereas rushes don’t.

It’s important to notice the small things in our environment. While grasses, sedges and rush are generally wind-pollinated and lack large showy flowers they have their own subtle beauty - sometimes you have to get up close and personal to see it.