Growing on basalt boulder in open lodgepole forest by Third Canyon.
This is distinguished from M. stygia by apparently broader, stubbier lobes, and more imporantly, distribution of pseudocyphellae exclusively along the margins instead of laminal.
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According to the key in the Sonoran Flora M. glabra and M. glabroides have no laminal pseudocyphellae. But you probably mean micropores? Those only show up on SEM, I think. Maybe a careful scalp section of cortex would show them in LM, too? In general, according to Trevor, all Parmeliaceae either have “macrovents” (pseudocyphellae such as M. hepatizon) or “microvents” (micropores that require SEM to see). So, you can at least indirectly infer their presence if you can find no macroscopic pseudocyphellae!
Alas, the stacker is frying my laptop (and that’s with the super-duper laptop cooler!), I’ll have to wait until tonight to run those photos again, otherwise I’m stuck twiddling my thumbs for the next several hours. Grumble.
Minute glass hairs? Oh gosh. They just get harder. So question, with that M. glabra can you see the pores/fenestrations with an LM, or is that just reserved to SEM?
Your photos of the pseudocyphellae are super helpful, glad you take the time to put them up, and with the arrows – was hard to differentiate them without the arrows… These Melano’s got me in a world of confusion here — I’ve been trying to key out some out, and so I dug up Blanco et al.‘s description on the new genera, even worked on the MO description of the three, and gosh I’ve gotten even more lost. It just seems like they should be so easy… they’re foliose!
Super grateful for your photos – hope those minute ?cortical hairs? show up in the stacked photos! Yay!
I sure wish I had photos like this when I was learning! :) It’s one of those things where you aren’t sure whether they’re there or not… until you finally see one which does have them. “Oh. So that’s what they look like. Duh.” :)
In all seriousness, though, they are pretty subtle. You have to look very carefully, and not all lobes will have ones as clear as they look in this photo. In some other species (M. tominii) they are even more subtle. I think I’ve tried, but couldn’t get a photo that showed them for that species.
Oh, which reminds me: there are two species here in southern California, M. glabra and M. glabroides which differ in a couple ways, but the most reliable character is supposedly the presence of minute glass-like hairs on the lobe tips. These things are so blasted tiny, I can barely convince myself I can see them, let alone get a photo of them. I just tried again last night, maybe this time I got lucky. The computer is busy stacking them as I write…
Those are tiny! And they can be seen with a dissecting scope, I wasn’t sure from Blanco et al.’s (2004) description whether an SEM is needed… and you show that its not, awesome!
Created: 2009-06-15 17:26:16 CDT (-0500)
Last modified: 2009-06-15 17:26:16 CDT (-0500)
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