Plant Species of the Bright Angel Trail:
Slender Cryptantha, Cryptantha gracilis
See Plant Guide to Bright Angel Trail for an introduction to this page, especially the Introduction To These Species Pages.
Identification status: 95%.
The identification is not 100% since I did not check the nutlets on this exact specimen. I did check out the nutlets on a specimen found later on the trail, and thought in the field that the later specimen was identical to this specimen. However, after working on the determination here, the later specimen may be a different species, C. fendleri, than the plant at mile 0.37. That later specimen had four nutlets, whereas C. gracilis is supposed to usually have just one nutlet, but can occasionally have up to three nutlets. It is also possible that the floras are incorrect, and C. gracilis can sometimes have four nutlets.
There are only three annual Cryptantha species found in this area of the South Rim above 4000 feet elevation: C. fendleri, C. gracilis, and C. pterocarya. C. pterocarya is easily recognized in the field by its honking calyx due to its winged nutlets, and is found only up to 5600 feet elevation.
C. fendleri and C. gracilis both have smooth, shiny nutlets, and are differentiated by McDougall as follows:
25 Plant not conspicuously bristly, the hairs rather short; nutlets 1-3 ...C. gracilis
25' Plant conspicuously bristly with white, spreading hairs; nutlets 4 ... C. fendleri
The plant from the Bright Angel Trail shown in the pictures below matches online pictures of C. gracilis in not having conspicuous bristles on its leaves or calyces, and in having dense appressed tawny hairs on its calyx. It does not match online pictures of C. fendleri.
In addition, the inflorescence spikes of C. gracilis never become elongate, whereas those of C. fendleri do.
Pictures of C. gracilis: SEINet - note the almost identical appearance of every feature to the plant from the Trail; Jim Andre's CALPHOTOS picture - note the almost identical appearance of the inflorescence, including the stem hairs and leaves, to the plant from the Trail.
Pictures of C. fendleri: Saskatchewan's Wildflowers - note the branching habit, and the bristly stems, leaves, and calyces; Cryptantha fendleri - note the long racemes in fruit; SEINet - note the bristles on the calyx and the branching habit.
From a SEINet search on 11 May 2008, there are four vouchers of this species from this area of the South Rim in the Coconino County portion of the Grand Canyon, including one on this trail from above 3 mile house. Others are at: Yavapai Point; and vicinity of Grandview. Note that there may be additional vouchers at other herbaria not available through SEINet.
There are three vouchers of C. fendleri from this area; two from Grandview and Grandview Trail, and one from El Tovar to Grand View.
First occurrence on Bright Angel Trail: mile 0.37, elevation 6650 feet (2027 m).
Number of plants along Trail: at least 20 plants were found in at least 3 different locations in May 2008.
From 4 May 2008, mile 0.37:
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.
Copyright © 2008 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: 13 May 2008