Plant Species of the Bright Angel Trail:
*smooth brome, Bromus inermis

See Plant Guide to Bright Angel Trail for an introduction to this page, especially the Introduction To These Species Pages.


This is a non-native species.

Identification status: fairly high confidence. It keys to this species, measurements from my pictures are consistent with this species, and there is a voucher from this trail nearby.

However, I've never seen this species before, and I don't know if it has any look-alike species. Also, keying from pictures is much more problematic than keying from a specimen in hand, since many important characteristics cannot be measured to use as confirmation of the determination.

Characteristics deduced from my pictures (note that these values are much more uncertain than real measurements made on a real specimen):

Stem: 4.2 dm, including inflorescence; possibly rhizomed
Leaves: 8 mm wide, flat; sheath open only 4-14 mm; ligule membranous
Inflorescence: ~11 cm; panicle with 3-4 branches per node
Spikelet: 2.6 cm, florets ~8
Glumes: ~7.5 mm, persistent, one typically ~1 mm longer than the other
Lemma: ~ 7 mm, with 3 clear converging veins, probably more faint ones; awn 0-0.4 mm

Keying from McDougall:

1b.   Not Hilaria
2b.   Glumes persistent
19b.  Spikelets stalked in an open panicle
40b.  Spikelets many-flowered
78b.  No id in 78a
82b.  Not Phragmites
83b.  No id in 83a
87b.  Lemmas at least awn-tipped
94b.  Not Dactylis
95b.  No id in 95a
98b.  Spikelets rounded
102b. Per
107a. Lemmas awn-tipped or very nearly awnless;
      creeping underground stems present ...  Bromus inermis

My observed characteristics are consistent with the Jepson Manual and Hitchcock and Chase descriptions of B. inermis. The pictures of my plants look consistent with the online pictures at USDA and SEINet. Also, none of the other species close to this in the key seem to fit.

The only other possible determination that comes to mind is Festuca, but the species at the Grand Canyon have rolled leaves and are clearly awned.

From a SEINet search on 28 September 2007, there are 7 vouchers of this species from the Coconino County portion of the Grand Canyon, including one from this trail at Indian Gardens. Note that there may be additional vouchers at other herbaria not available through SEINet.

First occurrence on Bright Angel Trail: mile 0.70, elevation 6388 feet (1947 m).

Number of plants along Trail: at least 30 plants were found in at least 5 different locations in September 2007, generally in moister areas.


From 5 September 2007, mile 0.70:

From 5 September 2007, mile 0.72, at Kolb Seep Springs:


See Resources for Grand Canyon Flora for further information on most of these references. Entries in the second column are either the name used in that source or a page reference. The name is linked to online pages when available. If a given reference does not contain this taxon, the entry is either left blank or contains a hyphen.

Scientific NameBromus inermis
1987 Grand Canyon Flora NameBromus inermis
1987 Grand Canyon Flora page15
SEINet Image PageBromus inermis
USDA PlantsBromus inermis
Flora of North America
Jepson Manual for California treatmentBromus inermis ssp. inermis
Jepson Manual illustration page-
Kearney and Peebles NameBromus inermis
Kearney and Peebles Page #77
Vascular Plants of AZ name
Vascular Plants of AZ volume: page
Huisinga et al 2006 name-
Huisinga et al 2006 page numbers-
Epple Name-
Epple description page #-
Epple pix #-
McDougall 1964 nameBromus inermis
McDougall 1964 page #49
Brian 2000 Name
Phillips 1979 name-
Phillips 1979 page #-
Stockert 1967 name-
Stockert 1967 page #-

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Copyright © 2007 by Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to me at this source:
Comments and feedback: Tom Chester
Last Update: 28 September 2007