Oxalis metcalfei

Alpine Woodsorrel - Oxalis metcalfei
Photograph immediately above and four below

Sawyers Peak Trail, Black Range, New Mexico, USA

On August 25, 2014, we took a walk along Sawyers Peak Trail, heading south from Emory Pass.  It was not a long walk but at 3.5 miles (round trip) we did venture out onto the east side of the ridge, looking down into the Percha drainage.  The trail is better than this time last year, last year it simply was not possible to see the trail in many places because of the tall grasses that the Forest Service had seeded with following the Silver Fire.  This year there are still healthy stands of grass but the trail is more clear.  There is only one major washout along this section of the trail.  

I had problems getting started, there were myriad wildflowers, numerous species and many individual plants.  It was a riot of color and the camera functioned as an anchor, stopping my steady progress up the trail.

Oxalis was blooming profusely.  In identifying these plants to species I considered O. metcalfei and O. violacea. was eventually ruled out because the plants we were seeing had "two distinct orange tubercles at the apex of the sepal" (not visible in these photographs).  In the Vascular Plants of the Gila entry (one of the first sources I review when identifying plants in this region) there is a distinction between O. metcalfei and O. alpina - the distinction being that O. alpina (Alpine Woodsorrel) grows at higher elevations.  It is with some difficulty that you get to elevations in the Black Range that are higher than the Sawyers Peak trail.  But I found specimen records which reported to be O. metcalfei at higher elevations in the range.  Then a bit of luck, I began to wonder if the two had been lumped into one species, which after more research proved to be the case.  I still do not know if there is some distinction between O. metcalfei and O. alpina (subspecies? variants less than subspecies?) but at least I can call the plant to species.

October 2019 Update:  I photographed this species at Iron Creek Campground in the Black Range on September 19, 2019 and revisited this speciation issue.  The species name on this page has been changed from O. alpina to O. metcalfei.  Flora of North America notes: "Oxalis metcalfei has mostly been identified as O. alpina (Rose) Rose ex R. Knuth, but the latter is a species of south-central Mexico, far from the populations in northwestern Mexico and the southwestern United States. Oxalis alpina has leaflets with dotlike oxalate deposits scattered throughout the lamina, concentrated near margins, or as continuous, filiform marginal bands around the lobe apices; the corollas usually are white. Oxalis metcalfei is consistently different in the nature of its foliar oxalate deposits and the corollas usually are purplish to lavender or pink."

Iron Creek Campground, Black Range
Photograph immediately above and two below
September 19, 2019

© Robert Barnes 2018-2023