The human female is taking for. ev. er to work her way through the Lepidium virginicum (Peppergrass) specimens out here at the herbarium, sorting each of them into one of two subspecies. Subspecies virginicum has glabrous (bald) fruit and pedicels (fruit stalks) that are round in cross-section and usually not more than 0.2 mm wide. Subspecies menziesii has glabrous or puberulent (with minute short hairs) fruit and pedicels that are flattened toward the top and usually more than 0.2 mm wide. Which all sounded well and good to her—until she started looking at hundreds of sheets and measured parts and parts and more parts and found that almost all of the Texas plants of both subspecies have the glabrous fruit, and the pedicels are–you guessed it–just about 0.2 mm wide exactly and maybe only a little bit flattened.
Face it, woman. NOBODY but you cares about things that are too small to see without a microscope. *I* don’t care. No one else in the herbarium cares. Other botanists don’t care. I doubt even the plants care. Why don’t you just slap any old name on the sheets and have done? I mean, who exactly do you think is going to call you on it? You’ll be long dead before anyone looks at these specimens again.
Norns save us, she’s going to try to figure it out anyway. She says there’s a sure-fire way to tell which subspcies a plant belongs to–it’s just nearly impossible to see. It involves making a cross-section of a seed and determining which way the embryonic seed leaves (cotyledons) lie inside of it.
Do you mean to tell me you’re going to take one of those little brown dots and cut it open to inspect its innards?! Don’t you have anything better to do with your time?
I can’t believe it! She’s actually going to try.
She has captured a seed on the little bit of putty under my foot. I guess the putty is to keep it from skittering away. I can barely see it–it’s scarcely a millimeter long. Sigyn can see it in a little more detail with her hand lens, but the human female is going to need to do this dissection with the highest power of her microscope.
Great Frigga’s Hairpins! She did it! She took a very thin blade, cut that little seed right across the middle, and then used a fine dissecting needle to tip the cut surface up so she can look at it. Ehehehe! Now she’s trying to take a photo through the micoscope with her phone. There’s a knack to doing that, one she decidedly lacks. Mostly she’s just waving the phone in the general direction of the eyepiece. She looks drunk.
Ugh. She is now trying to teach us how to recognize the different types of seed leaf arrangements. Again, I don’t care, but Sigyn is interested, so I’ll show you the photos she eventually managed to capture through blind luck.
In subspecies menziesii, the radicle (embryonic root) and the two cotyledons line up in a row. The cotyledons are termed incumbent.
Here, I’ll label it with my magic.
In subspecies virginicum, the cotyledons are accumbent. They lie flat sides together, edge-on to the radicle.
Again with the label magic, and to help my sweetie remember, I’ll toss in a handy mnemonic doodle.
“If it looks like a bunny a-comin‘, the cotyledons are accumbent.”
(I can’t believe I wrote that. The things I do for love…)
Sigh. How many folders of these plants are there to work through? Yeah, next time, I bring a book.