Plant Species of San Jacinto Mountain: High-Elevation Grass Species

This is just a very rough draft page to list the higher-elevation grass species of San Jacinto Mountain, for Tahquitz Valley and above (above the elevation of Caramba at 6600 feet), and show some pix of them.

List of Genera and Key
Species Links

List of Genera and Key

There are 11 genera found in this area:

Two of the genera have just one species present in each, which are easily recognized by their appearance:

The other nine genera can be easily keyed out by simply counting the number of florets / lemmas per spikelet, and noting whether the lemmas are awned or not:

Key to other nine genera

1. floret 1

2. awn > 15 mm.........Achnatherum
2'. awn < 4 mm
3. glumes > lemma.........Agrostis
3'. glumes < lemma.........Muhlenbergia

1'. florets 2-11

4. leaf blade thread-like, width 0.5-1 mm; infl narrow; florets 2; glumes > lemmas.........Deschampsia elongata
4'. leaf blade gen flat, width 0.5-17 mm; infl narrow to very wide; florets 2-11; glumes < lemmas
5. lemma not awned
6. Pl 6-15 dm; lf blade 4-12 mm wide; lemma rounded on back, strongly 5-11 veined, veins not converging to tip; glumes 0.8-1.5 mm long.........Glyceria
6'. Pl 1.5-10 dm; lf blade 0.5-5 mm wide; lemma gen compressed, weakly 5 veined, veins converging to tip.........Poa
5' lemma awned
7. awn attached below lemma tip; florets gen 2-3.........Trisetum
7'. awn from lemma tip; florets 2-11
8. infl spikelike, florets 1-3 per node.........Elymus / Elytrigia / Leymus
8'. infl open, often nodding or drooping, florets 1 per node.........Bromus

glumes > lemmas means the glumes are longer than the lemmas, and hide at least the lowermost lemma entirely.

glumes < lemmas means the glumes are shorter than the lemmas, and never hide the uppermost portion of the lowermost lemma.

Species Links

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Copyright © 2009 by Tom Chester.
Commercial rights reserved. Permission is granted to reproduce any or all of this page for individual or non-profit institutional internal use as long as credit is given to me at this source:
Comments and feedback: Tom Chester
Updated 1 September 2009.