Plant Species of the Bright Angel Trail:
threadleaf common rabbitbrush, Ericameria nauseosa var. oreophila
See Plant Guide to Bright Angel Trail for an introduction to this page, especially the Introduction To These Species Pages.
This species is known to most botanists in southern California as Chrysothamnus nauseosus ssp. consimilis. This species was only recently transferred to Ericameria, with a change in the subspecies name at the same time. See New Names for These Subspecies.
Identification status: high confidence, but not without a struggle; see Chrysothamnus nauseosus (=Ericameria nausosa) Subspecies With Glabrous Involucres At And Near The Grand Canyon, Arizona.
There are two subspecies of rabbitbrush on this trail, which are very easy to tell apart when they are in bloom. Variety oreophila is found only on the upper part of the trail, and it has leaves present at bloom time. Variety juncea is found only below 4300 feet elevation, with the first specimen at mile 3.65. It has no leaves present at bloom time. Compare the pictures of var. oreophila in this page with pictures of var. juncea found farther along the trail. Variety juncea is also a significantly shorter plant.
Rabbitbrush is one of my all-time favorite species. It produces lovely, sometimes stunning, displays, at a time of the year when there aren't many blooms around. In southern California, it does this without any summer rain at all, even in the desert! You just have to love a species that can manage this amazing feat that goes so far beyond just survival that one can hardly believe it.
The displays around the Grand Canyon Village area are among the most beautiful displays I have seen. The plants clearly make good use of the summer rainfall here.
When I first saw these plants back in 2003, I thought they looked very close to our specimens of Chrysothamnus nauseosus ssp. consimilis, but I never had time to determine them until 2007. It was a bit surprising to find out that they really were the same taxon. I expected that the individual subspecies of any species that has 21 subspecies would not be very widespread!
From a SEINet search, there are 3 vouchers of this taxon from the Coconino County portion of the Grand Canyon, including one from this trail collected by the famous Alice Eastwood and two other nearby vouchers. Note that there may be additional vouchers at other herbaria not available through SEINet.
First occurrence on Bright Angel Trail: mile 0.02, elevation 6834 feet (2083 m).
Number of plants along Trail: This species is quite abundant along the upper part of the trail; at least 50 plants were found in at least 9 different locations in September 2007. You can see almost 20 different plants in bloom in the first picture below in ~0.01 mile of the trail!
From 5 September 2007, mile 0.02, the first plants on the trail:
The next picture shows a plant near the closest tourist in the above picture. Note the large amount of green in the upper half of the plant; these are the leaves, which are present at flowering:
In the next picture, note the thread-like leaves. I measured a number of leaves on the trail in September 2006, and they were mostly ~0.5 mm wide.
In the next picture, note that the phyllaries are in distinct vertical rows. If you have sharp eyes, you can note that there are five flowers per head (see a later picture below for a better image of the five flowers per head).
From 14 September 2006, along road from Yavapai Lodge to Visitor Center:
Something bad has happened to a few heads in the following picture, causing them to turn red and then drop off. I don't' recall ever seeing this happening on any other specimen I've seen.
In the following picture, I've labeled the five flowers from one head, and also noted the stigma and the style appendage from another flower. The length of the stigma is about the same as the length of the style appendage, consistent with the description of var. oreophila in the Flora of North America. The length of the stigma is less than the length of the style appendage for var. graveolens. (Picture was incorrectly labeled prior to 20 August 2013; thanks to Tom Schweich for the correction. See his higher resolution scan showing the stigmatic portion of the style much more clearly.)
Note the thread-like leaves in the following picture:
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.
Oddly, the 1987 Grand Canyon flora, and the current online park list, does not contain this variety; possibly it was confused with var. graveolens in the past, which is in both lists.
Family Asteraceae Scientific Name Ericameria nauseosa var. oreophila 1987 Grand Canyon Flora Name - 1987 Grand Canyon Flora page - SEINet Image Page Ericameria nauseosa USDA Plants Ericameria nauseosa ssp. consimilis var. oreophila Flora of North America Ericameria nauseosa var. oreophila Jepson Manual for California treatment Chrysothamnus nauseosus ssp. consimilis Jepson Manual illustration page (231 shows different subspecies) Kearney and Peebles Name Chrysothamnus nauseosus var. consimilis Kearney and Peebles Page # 865 Vascular Plants of AZ name Vascular Plants of AZ volume: page Huisinga et al 2006 name Ericameria nauseosa Huisinga et al 2006 page numbers 208-209 Epple Name Chrysothamnus nauseosus Epple description page # 265 Epple pix # 460 McDougall 1964 name Chrysothamnus nauseosus McDougall 1964 page # 236 Brian 2000 Name Phillips 1979 name Phillips 1979 page # Stockert 1967 name Chrysothamnus nauseosus Stockert 1967 page # 30
Copyright © 2007-2013 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: 27 September 2007 (one error corrected on 20 August 2013)