This is my first post to the iNaturalist forum so forgive me if I do something wrong. I’ve been thinking since it is getting warmer where I live that I’d like to start taking photos of grasses, sedges, and rushes and posting them to get a better understanding of what I’m looking at in my region. My question is what are the defining characteristics for the order poales that are most often used for identification?? and can these parts of the plants be photographed using something as simple as a macro lens attachment for a smartphone? I look forward to seeing the discourse and information thats available.
Most characteristics used can be divided in two parts, vegetative (leaves, stem and roots) and generative, for the first start with general picture of a plant, make sure it’s seen how it grows (does it form a bump on the ground, or it’s spreading just above the soil, etc.), take a pic of the stem and its shape, then look at leaves, for stem and leaves you should be able to see hairs on them, esp. for poaceae take a picture of the highest leaf base (you can move the leaf from the stem so all structures are seen).
Then look at the flowers or seed, take a picture of the whole thing, make sure that arrengement of “branches” is well seen, for many species the lowest part of inflorescence is crucial, then take a shot of one flower group, then take it apart and find a single flower with all the leaves that make it, take enough photos so structure of every part is visible, similar to:
For sedges often seeds are the only way to properly id the species, so take them out and show their shape, colour and size.
Using school-type pics are easy to explain the matter, so if you still have your botany book, check it.)
Size/shape/arrangement of the seed capsules is generally the key thing to look at. Although leaf proportions can also be important features to get in there.
I have a small field guide to grasses and relatives and its key starts by sorting them into triangular vs. round stems and then looking at the shape of the inflorescence. It’s a fairly slim book and simplifies a bit and only hits the most common species, but thanks to its pictures it’s very easy to use for someone who doesn’t know much about grasses to start with. (The Look Inside feature on its Amazon page shows some example illustrations.)
thanks for the replies and valuable information, I can’t wait to put it all into practice!
To understand about grasses, let me use birds as an analogy: if the only identification materials we had were the ones that banders use for birds in the hand, we would think that birds are hard to identify.
What does this have to do with grasses? Keying out grasses will have you looking through a hand lens at the ligules, whether the sheath is open or closed, the number and shape of glumes and lemmas, and all that. Then, once you have gone through all those keying steps, you step back and see that Lolium perenne is visually very different from Bromus diandrus, which is again visually very different from Holcus lanatus. Having determined each of these species, you will from then on be able to distinguish them by sight as easily a birder can distinguish birds.
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