Plant Species of the Bright Angel Trail:
Miners Lettuce, Claytonia parviflora ssp. utahensis
See Plant Guide to Bright Angel Trail for an introduction to this page, especially the Introduction To These Species Pages.
Identification status: 100%. The fused cauline leaves immediately under the flower spike are distinctive, as are the linear-narrowly spatulate basal leaves.
Although there is no doubt about what entity these plants are, what to call that species is the subject of considerable debate. C. parviflora is part of the C. perfoliata complex. Botanists are divided as to whether to lump all the defined subspecies of C. parviflora and C. perfoliata into a single variable taxon under the name of C. perfoliata (or under the synonym of Montia perfoliata), or to treat them separately.
We have the same problem in California, and I haven't yet made up my mind which treatment is preferable. Sometimes the individual taxa seem to make sense as valid taxa; sometimes they don't.
Plants at the Grand Canyon have historically all been lumped under the name of C. perfoliata, and were treated that way in McDougall, Kearney and Peebles, Phillips et al., and the current online version of the Grand Canyon Flora. The 2003 Utah Flora lumps them all under M. perfoliata; it is especially interesting that the Utah flora does not accept ssp. utahensis!
However, the 1993 Jepson Manual for California, the 2003 Flora of North America Claytonia treatment, and the 2006 Vascular Plants of Arizona treatment, all accept the individual taxa.
Every one of the hundreds of plants I saw along the upper Bright Angel Trail in May 2008 clearly fit Claytonia parviflora, with linear-narrowly spatulate basal leaves, and thus that name seems more appropriate to describe these plants. However, their subspecies might be best described as not viridis, for two reasons. First, subspecies viridis is distinctive due to its non-round cauline leaves, and these plants are not that taxon. Second, the other two subspecies are not clearly distinct. The 2006 Vascular Plants of Arizona treatment says:Subspecies parviflora and utahensis seem to be distinct only in their respective geographic ranges. Subspecies utahensis is found north of the Mogollon Rim, whereas subsp. parviflora is found south of the Mogollon Rim. We observed a large amount of variability in basal leaf shape, which, according to [the Flora of North America (2003)], delimits these subspecies.
But since it would be too confusing to call these "ssp. not viridis", I will follow the Vascular Plants of Arizona and assign these plants to ssp. utahensis, although it is fine with me if anyone else wants to lump them under C. perfoliata or M. perfoliata.
Distribution maps for the individual taxa from the Flora of North America: C. parviflora ssp. parviflora; C. parviflora ssp. utahensis. See also the Arizona distribution map in 2006 Vascular Plants of Arizona treatment.
From a SEINet search on 12 May 2008, there are two vouchers of this taxon from the Coconino County portion of the Grand Canyon, including one from this trail near the Colorado River at the bottom. There are also two vouchers of C. perfoliata on this trail, from Indian Gardens and 5500 feet. Since I observed the plants at 5500 feet on this trail, and they do not fit the narrow definition of C. perfoliata, it is clear that at least that voucher is using the lumped name. Note that there may be additional vouchers at other herbaria not available through SEINet.
First occurrence on Bright Angel Trail: mile 1.27, elevation 5920 feet (1804 m).
Number of plants along Trail: at least 99 plants were found in at least 9 different locations in May 2008, the maximum numbers recorded for each quantity.
From 4 May 2008, mile 1.27:
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