Plant Guide to Bright Angel Trail

This page has been superceded by a more recent detailed guide to the Bright Angel Trail beginning at the trailhead.

Introduction and Explanation of Plant Trail Guides

Highlights of This Trail
Fieldwork Dates and Summary of List Changes With Time
The Plant Guide
Comments On Specific Species


This is a preliminary attempt at noting the locations and identifying the plants along the Bright Angel Trail above Indian Gardens. The guide gives the location of the first occurrence of each taxon on the hike out of the Canyon, and hence is most useful only in that direction. Of course, the reason is that one has much more time to look at the plants on the way up!

Note that I am NOT an expert on Arizona plants or desert plants of California! Most of my botanical experience has been with plants of the California Floral Province in Southern California. Thus there are many taxa that remain unidentified from my first look at the Grand Canyon flora here. And of course, many of the taxa cannot be identified without seeing them in Spring, when they are blooming.

Most of the identified taxa were not the result of keying out the specimens. In fact, I keyed out only two taxa: Virgulus falcatus and Eriogonum microthecum, with the var. laxiflorum coming from the locations given in the Annotated Checklist of Vascular Plants of Grand Canyon Park 1987. Instead, most of the identifications came from using the observed characteristics noted from a quick study while hiking past them out of the Canyon, along with the Grand Canyon Checklist and information about those species found in floras and online. This usually, but not always, results in correct identifications. Caveat emptor!

The sources I used for the identifications are noted in Resources for Grand Canyon Flora.

Because I only get to the Grand Canyon about once per year, it is unlikely that this guide will progress very rapidly with just my observations. If you can reliably identify any of the species along this trail, I would be happy to add your identifications to this guide, with credit to you for those identifications. If any botanist living close to the Canyon would like to take this as a project, you are welcome to take this list as a starting point and turn it into a highly complete and reliable list, like ones I have done for some trails in Southern California. (See Vernal Pool Trail, Santa Rosa Plateau, for an example.) I would actually prefer that alternative, since I would love to be simply a user of this guide, instead of the creator of this guide. (;-)

Of all my trail guides, this guide has by far the most accurately located plants, even if it so far contains one of the lowest percentages of identified taxa. The Bright Angel Trail is, as far as I know, the most-accurately surveyed trail in the world. See Pedometer Accuracy. In the plant guide here, I have tied all my pedometer readings to the Control Points (CP in the guide below) from the Bradford Washburn et al publication referenced in that webpage. All the reported elevations also come from that publication.

Latin and common names follow the usage in the Grand Canyon Plant List available as a Microsoft Word Document linked from Grand Canyon National Park: Plants. If common names were not given, I usually used the common names in my database for California plants.

Jepson Manual Latin names are given as links from the Latin Name on this page.

Highlights of This Trail

A preliminary analysis of the species that are identified below, or have likely identifications with plants on the Grand Canyon Trail list, shows that nearly all of these taxa are found in Southern California as well, primarily in the Desert Mountains (DMtns province of the Jepson Manual of Higher Plants of California).

This may not be a surprising finding, since one could perhaps argue that the Colorado Plateau is similar to one of the Desert Mountains in California, just several orders of magnitude larger. But it was surprising to me, for two reasons:

  1. The Colorado Plateau area of Utah, Colorado, New Mexico and Arizona is a fairly uniform region in its geology, geography, and climate; all of which are very different from California.

  2. The Grand Canyon gets about half of its rainfall in the summer, a strikingly different situation than the California Desert Mountains. For example, quaking aspens, Populus tremuloides, are only found in a single location in Southern California, the area of the San Bernardino Mountains that gets the greatest amount of summer rainfall (Krantz 1994). The proportion of rainfall that falls in the summer there is miniscule compared to the Grand Canyon, only 10% at most, far from the ~50% of the Grand Canyon.

    The Grand Canyon gets about 14.5 inches of rainfall per year at Grand Canyon Village on the South Rim at 6970 feet, and less than 8.5 inches per year at Phantom Ranch at the bottom of the Inner Canyon at 2560 feet. The highest Desert Mountains of California get around 10 inches of rainfall per year, with less than 30% of that rainfall occurring in summer.

I therefore expected most of the species at the Grand Canyon would be found elsewhere in the Colorado Plateau, and not in California, which turned out to be incorrect.

Of the 37 taxa with Latin Names given in the guide, 31 (84%) are also in the Jepson Manual. Of those 31, all but 4 are found in one of the Desert subareas of the Jepson Manual. (Those 4 are found in the coastal mountains of Southern California, which reach higher elevation than our Desert Mountains.)

Of the 6 taxa not found in the Jepson Manual, 4 are found in the Colorado Plateau and neighboring states, with the other 2 ranging up to Idaho and British Columbia, respectively.

Until a survey of the trail is done in the springtime, to catch those annuals missing from a survey done in September, I can't be sure how representative the above results are. It is possible that taxa seen in late summer are a population more similar to those in California than ones seen in spring. My guess is that this is not the case, since spring-blooming annuals live a life-cycle similar to that in California, whereas I would have thought that Arizona might have a unique set of plants that depended on the summer rainfall. But only data will give the answer.

Another possible bias in the above results might result from my identifying plants also in California at a higher rate than ones not present in California as well. While this bias has to operate at some level, it is probably not highly significant, since I am not familiar with about half of the identified plants. Of the 31 taxa observed here that are also present in California, I have never seen 15 (48%) of them before on any trail in California (because I haven't botanized any of the California Desert Mountains so far). So although it is likely that analysis of the complete list for the Bright Angel Trail would have a lower percentage of taxa also present in California, that percentage is still going to be well over 50%. Even if all the unidentified taxa turn out to be non-California taxa, which is very unlikely to be the case, still 43% of the taxa on this trail will also be found in California.

Number of Unique Taxa On This Trail

The following histogram gives the number of trails in my database that contain each taxon on this trail. I had 1 trail in my database when this histogram was made. A number of "1" means the taxon has only been found on this trail among the trails in my database.

This table will only be populated when I have more than one trail plant guide in the Grand Canyon! (I have over 65 trails in my Southern California database, but the following table will summarize only Grand Canyon trails.)

Number of Trails
Containing A Taxon
Number Of Taxa
On This Trail
% of Taxa
On This Trail
Total Taxa 100%

I found x additional species not in the above table, since they have not been identified yet. The unidentified ones are marked with ? or sp in the id? column in the guide.

Fieldwork Dates and Summary of List Changes With Time

The following table gives the dates the trail was walked and taxa recorded. After each visit, the table gives the total number of taxa on the list and the breakdown of the taxa without positive identification. See Explanation of Plant Trail Guides to understand the symbols below.

Visit DateVisit ## taxa# "?"# "sp"# "~"# "ssp"

The fieldwork on 9/11/03 was done only incidentally on a day hike to Plateau Point, and only is fairly complete for the plants beginning about 0.25 miles above the junction with the Plateau Point Trail.

The Plant Guide

Version for printing, without lines and other text on this page (5 pages)

MileS#id?Common NameLatin Name#here#all
0.00   Begin plant guide heading to the Rim at the lower end of Indian Gardens at the Plateau Point Trail Jct (right); the mule staging area (right); and the bathrooms (left), CP #36, elevation 3763'. The plant guide only begins to be more complete 0.25 miles from here.
 r1 sacred DaturaDatura meteloides+1 / 1 
 l2 common reedPhragmites australis10 / 1 
0.25l3 Apache plumeFallugia paradoxa20 / 9 
0.25b4 catclaw AcaciaAcacia greggii var. arizonica30 / 5 
0.25b5sptulip pricklypearOpuntia phaeacantha /  
0.26r6spmormon teaEphedra viridis30 / 9 
0.26r7 button brittlebushEncelia frutescens10 / 5 
0.27r  Sign: "The plants you see here are the living desert. They grow by the inch and die by the foot".
0.27r8spbroom snakeweedGutierrezia sarothrae99 / 9 
0.28r9sprabbitbrushChrysothamnus sp.99 / 9 
0.28r10?unk shrub? /  
0.28r  Sign: "Indian Gardens" (arrow pointing to the right, downhill)
0.29l11?Colorado four o'clockMirabilis multiflora10 / 5 
0.32   Cross creekbed; CP #34, elevation 3884'.
0.32r12?tarragon look-alike with Brickellia flowers.?+99 / 9 
0.33r13spfragrant ashFraxinus cuspidata var. macropetala50 / 9 
0.34r14?unk shrub? /  
0.37r  Creekbed is now close.
0.42 15 silverleaf nightshadeSolanum elaeagnifolium10 / 2 
0.43r16spNative American pipeweedEriogonum inflatum var. inflatum+1 / 1 
0.46b17?tarweed with 3 ~reflexed wide ligules?30 / 5 
0.48l18spdollarjoint pricklypearOpuntia chlorotica1 / 1 
0.48l19 one-sided grass?5 / 5 
0.51 20spgranite giliaLeptodactylon pungens ssp. brevifolium10 / 5 
0.51l21 slender buckwheatEriogonum microthecum var. laxiflorum99 / 9 
0.53l22?needlegrass?Stipa sp.?20 / 9 
0.55l23splike ripgutBromus sp.5 / 1 
0.55r24?tall tumblemustardSisymbrium altissimum5 / 1 
0.56   Switchback left.
0.59   Curve right 90°, cross streambed, then turn left 90°; CP #33, elevation 4029'.
0.70l25?unk shrub like scrub oak?+30 / 9 
0.76   Cross creekbed, with high-pressure water pipe elevated on right; CP #32, 4093'.
0.77r26?saltbush??1 / 1 
0.78r27 Utah agaveAgave utahensis1 / 1 
0.78 28?dead annual like sweet alyssum?+99 / 9 
0.86l29spyuccaYucca sp. /  
0.87r30 Utah juniperJuniperus osteosperma10 / 5 
0.87r31?tree with lvs like alder x fremont cottonwood? /  
0.87r32?per. mallow??30 / 9 
0.99   Long switchback right, cross streambed; CP #31, 4208'.
1.06   Switchback left; CP #30, 4255'.
1.13l33?like hedge nettle?10 / 3 
1.14r34?unk dead annual like mentzelia or goldenrod?1 / 1 
1.20l  (twoneedle pinyon?, Pinus edulis?)
1.20r  (Gambel's oak?, Quercus gambelii?)
1.23   Trail curves right 90°.
1.24   Switchback left; CP #29, 4396'.
1.27   Switchback right.
    Curve left 90°.
    Switchback left.
    Curve right 90°.
    Switchback right.
    Curve left 90°.
1.38r35spFremont's goosefootChenopodium fremontii5 / 2 
1.39   Switchback left at the closest part of the trail to the "Petrified Snow" (caused by falling rocks chipping off the red coat on the Redwall Limestone due to the Supai Group above, exposing the natural gray/white color). CP #28, 4512'.
1.42   Curve right 90°.
1.42   Switchback right.
1.42b36 *cheatgrassBromus tectorum99 / 9 
1.43r37?low shrub with a leaf like a honking coffeeberry leaf? /  
1.45l38?asteraceae with alt leaves like gutierrezia X galium? /  
1.45l39spthistleCirsium sp.5 / 3 
    Curve left 90°.
1.47   Switchback left.
1.47l40?like morning glory or wild cucumber, lvs both opp and alternate?3 / 1 
1.47r41spMunz's bedstraw or Watson's bedstrawGalium munzii or Galium watsonii+5 / 3 
1.52 42?like matchweed but with no ligules; lvs petioled with wedge-shaped bases? /  
1.52   Switchback right.
1.53   Switchback left.
1.55   Switchback right.
1.59   Switchback left; CP #27, 4663'.
1.65r43 *red bromeBromus madritensis20 / 2 
1.67   Switchback right.
1.68l  Jct. short path to 3 mile Resthouse; CP "(3 mile) Resthouse", elevation 4721'.
    Curve left 90°.
    Curve right 90°.
1.83 44 white prairie daisyVirgulus falcatus99 / 9 
1.84   Switchback left; CP #26, elevation 4855'.
1.88l45 twoneedle pinyonPinus edulis10 / 9 
1.89r46spCalifornia brickellbushBrickellia californica20 / 9 
1.90   Switchback right, CP #25, elevation 4897'.
    Curve left 90°.
    Curve right 90°.
1.94r47spgrass with panicle infl with spikelets at end of branchlets?30 / 5 
1.97   Switchback left; CP #24, elevation 4955'.
2.00   Switchback right, CP #23, elevation 4978'.
2.00l48?radiate daisy with 8 well-spaced 3-lobed ligules like Hymenoxys?3 / 1 
2.10   Trail turns right 90°.
2.16   Switchback left; CP #22, 5056'.
2.20   Switchback right; CP #20, elevation 5133'.
2.25   Switchback left; CP #19, elevation 5165'.
2.28 49spsmall prickly pear with very long spines like on Tonto platform.Opuntia sp. /  
2.29   Switchback right; CP #18, elevation 5197'.
2.31l50sptrumpet gooseberryRibes leptanthum30 / 9 
2.31l51 skunkbush sumacRhus trilobata1 / 1 
2.33l52?like wormwood, Artemisia ludoviciana.? /  
2.35   Switchback left; CP #17, elevation 5244'.
2.43   Switchback right; CP #16, elevation 5305'.
    Trail turns right 90°; CP #15, elevation 5407'.
2.67   Switchback left at 2 mile corner; CP #14, elevation 5443'.
    Long switchback left; CP #13, elevation 5518'.
2.80r53spsnowberrySymphoricarpos sp.30 / 9 
2.84l54 Gambel's oakQuercus gambelii99 / 9 
2.87r55?old infl like California plantain?5 / 1 
2.87r56spWright's bedstrawGalium wrightii Gray+1 / 1 
    Trail curves right 90°; CP #12, elevation 5582'.
2.91r  "Shade View" - overhanging boulders giving shade with a great view.
    Trail curves right 90°; CP #11, elevation 5644'.
3.06   Switchback right at the 1.5 mile restrooms; CP #10, elevation 5692'.
3.08l57?desert phloxPhlox austromontana1 / 1 
3.10   1.5 mile Resthouse; CP "(1.5 mile) resthouse", elevation 5714'.
3.12r58?spiny shrub with small round petioled lvsCeanothus greggii?1 / 1 
    Trail bends left 90°.
3.18l59 Palmer's penstemonPenstemon palmeri10 / 5 
    Trail bends left 90°; CP #9, elevation 5780'.
3.22l60?unk ~vine with alt lvs?5 / 1 
3.24r61?like olive but a shrub.?1 / 1 
3.27l62?larger grass?5 / 1 
3.27r63?grass similar to Agropyron?5 / 1 
3.37   Switchback left.
3.38   Switchback right; CP #8, elevation 5900'.
3.41l  Check if the more scapose penstemon here is the same as earlier.
3.44   Switchback left; CP #7, elevation 5946'.
3.46r64?spherical head of small white to blue-purple flowers with 4 petals interspersed between 4 green sepals; linear serrate leaves, fr linear.?10 / 2 
3.47r65?unk similar to spreading dogbane?5 / 1 
3.48   Switchback right.
3.51r  Check for different yucca sp. here.
3.52   Switchback left; CP #6, elevation 6007'.
3.53r66~hoary asterMachaeranthera canescens20 / 3 
3.56   Switchback right.
3.60   Switchback left; CP #5, elevation 6073'.
3.63   Switchback right.
3.67   Trail curves left 90°.
3.70   Switchback left; CP #4, elevation 6153'.
3.71r67?unk shrub like alder with alternate large elliptic lvs? /  
3.73   Long switchback right.
3.74r68~smooth spreading four o'clockMirabilis oxybaphoides5 / 1 
3.78r69sspcoral bellsHeuchera versicolor var. versicolor+5 / 1 
3.78   Switchback left; CP #3, elevation 6218'.
3.79r70 Fendler's meadowrueThalictrum fendleri10 / 2 
3.81   Tunnel #2; CP "Tunnel (#2)", elevation 6248'.
3.90r71spsquirrel tailSitanion hystrix+10 / 1 
3.95   Switchback right; CP #2, elevation 6364'.
3.96l72?grass with carex-like infl with ~6 closely-spaced spikelets?5 / 1 
3.96l  Kolb Drip Spring
4.00r  Jct. path.
4.13l  Signposts that formerly held the sign indicating the contact between the Kaibab and Toroweap Formations.
4.28   Switchback left; CP #1, elevation 6630'. Guide incomplete past this point due to darkness.
4.51   Tunnel #1; CP "Tunnel (#1)", elevation 6761'.
4.59   Switchback right.
4.68   Bright Angel Trailhead; CP "S. Rim", elevation 6845'.

Comments On Specific Species

Datura meteloides. Datura wrightii in the Jepson Manual.

tarragon look-alike with Brickellia flowers. This shrub has leaves and habit that are very similar to tarragon, Artemisia dracunculus, in Southern California. However, these plants get much bigger than ones I've seen in Southern California, up to 6 feet tall and 10 feet across, with very thick woody stems. The flowers have the habit of those of Brickellia.

Eriogonum inflatum var. inflatum. One stem had a distinctly inflated portion, but three other stems on the same plant did not.

two unknown taxa. Both of these taxa were found much earlier, but not noted at the time.

Galium munzii or Galium watsonii. These plants strongly resembled Galium parishii in Southern California, with two unequal pairs of ovate leaves. The Jepson Manual lists Galium multiflorum as a synonym for G. watsonii, but the Jepson Manual distribution is n SNH, GB; NV, whereas the Flora of Arizona gives it as Idaho and Oregon to northern AZ. Those don't sound like the same taxon to me.

Galium wrightii. This plant resembled Galium angustifolium in Southern California, but had two unequal pairs of linear leaves.

Heuchera versicolor var. versicolor. Heuchera rubescens var. versicolor in the Jepson Manual.

Sitanion hystrix. Elymus elymoides in the Jepson Manual.

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Copyright © 2003 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
Updated 16 September 2003 (link to main Grand Canyon page added 22 September 2006; notice that this page is now obsolete added on 23 September 2007).