grasses

[clickie]

As I've mentioned, this weekend I attended a workshop sponsored by the Jepson Herbarium about grasses, family Poaceae. I paid $200 for the privilege of spending the weekend staring at grass under a dissecting scope.

I loved it. I didn't realize how much I miss staring at plants under a scope, figuring out morphological differences between different species and genera, and learning and using tons of new jargon. I learned how to identify about seven or eight genera of grasses with some reasonable accuracy, and how to use the Jepson key to figure out if I'm right.

A sampling of cool terms I learned this weekend:
spikelet - a single grass inflorescence, consisting of glumes and florets
glume - leaf bracts subtending the spikelet
lemma - the bract subtending the floret
palea - the first bract of the floret, right above the palea
ligule - the bit of tissue right at the part of the leaf where the blade meets the sheath
awn - long spiky thing on a spikelet, usually on either the lemma or glume

Bromus have long awns, spikelets consisting of more than five florets.
Festuca have smaller awns, smaller spikelets than Bromus, more widely spaced spikelet structure.
Melica have closed sheaths, papery glumes, no awns, a terminal floret structure, and relatively compact florets.
Poa have no awns, compact florets.
Avena have two glumes with awns, glumes enclosing the two florets.
Hordeus have triads of spikelets and awn-like glumes.
Nassella have hard lemmas with long awns that enclose the palea entirely.

See, now I can bore people with plant chatter on a whole new level! Fear me!

Comments

[snowy-owlet.livejournal.com]

Okay, I've been grousing for years about the green lawn turf we're all used to not actually being native to this hemisphere. Am I correct or not?

[clickie]

I don't know! We were looking at grassland grasses, and didn't really discuss lawn grass. But it's certainly possible and likely that it isn't native. It depends on what lawn grass you're talking about, as there are lots of lawn grasses. Some varieties of fescue and bluegrass are native to parts of this hemisphere, and some are not. I know a lot of the annual grasses that we see now on the California grasslands are actually Eurasian invaders, but I'm not sure about lawns.

[snowy-owlet.livejournal.com]

Okay! I'll keep grousing unless informed otherwise.