This is almost the only picture of Prunus murrayana ; this nice site is roughly a web version of A FIELD GUIDE TO TEXAS TREES, Simpson, Benny J. ; ISBN 10: 0877191131 / ISBN 13: 9780877191131 ; Published by Texas Monthly Pr, 1988
From the Prunus murrayana entry in FNA it appears that it is hairy everywhere; also note that are 2 path in Prunus key leading to P.m.
There are no observation in gbif.org , just about 50 herbarium entries, some of which with pictures . BUT 11 have coordinates and location indications :) https://www.gbif.org/occurrence/search?taxon_key=3022173
10 observation in gbif.org with coordinates from year 1997 are related to this paper by M. F. Enquist : https://www.biodiversitylibrary.org/partpdf/175811
where he identified the hairy specimens in Edwards Plateau as P. murrayana .
I extracted the relevant columns from the gbif Prunus murrayana data, resulting in a CSV file that is importable in http://umap.openstreetmap.fr/ ( or certainly other map tools ) : http://jmvanel.free.fr/Botany/Prunus_murrayana.csv
So one can see that these observations of 1997, and one of 1947, are around Sonora, plus one near Alpine.
But it can be expected in Trans Pecos, in “rocky stream banks, canyons, dry washes, fence rows”, particularly in Davis Mountains, Glass Mountains. Del Norte Mountains (cf links above).
So there is room for observations in inat’ ! I’ll try during my stay on April 4-19 .
Indeed , this is the only other live picture , except the herbarium ones.
Alas it says: Private land, Brewster CO, TX.
The photo does not contradict the FNA description.
What is interesting is that it flowers in the Trans Pecos. As written in paper by M. F. Enquist : The known populations of P. murrayana, all west of the Pecos River, have never been known to set fruit.
Note that in this paper there are tens of other locations of specimens examined, like Jailhouse Canyon on Iron Mountain Ranch in Glass Mountains, both sides of creekbed in limestone, 22 Mar 1994, P. Manning 728 (SRSC); . I will study this.
For now I put on this map the 11 coordinates from gbif.org: http://umap.openstreetmap.fr/fr/map/prunus-murrayana_1021186#8/30.867/-102.228
I began to put on this other map points from the textual descriptions: https://caltopo.com/m/K2L8P
I’ll be in Alpine around April 8 , join me to track Prunus murrayana !
Murray Plum is one of the rarest and least known trees in Texas. Certainly it is the rarest of all the plums. It is also of interest because, since its discovery more than half a century ago (April 21, 1928), no one has seen this plant with fruit.
Murray Plums usually occur as shrubs, but in a small grove of 30 or 40 plants in Jail Canyon in the Glass Mountains they are single-trunked and 12 to 15 feet tall. These trees are spaced 6 to 20 feet apart and give the impression that they were once a dense thicket that has been browsed out, probably by mule deer. I have also seen this plant as a thicket-forming shrub of 3 to 6 feet tall near Altuda Mountain in the Del Norte Mountains. Murray Plum was discovered in the Davis Mountains, and it is thought to be present on Eagle Mountain. In both places, the soil is igneous in origin. It also appears to be growing on igneous soil in the Del Nortes, but it is on the Capitan Reef limestone formation in the Glass Mountains. The plant could possibly be found in the Guadalupe, Apache, Delaware, and Santiago mountains if these were searched thoroughly.
Altuda Mountain in the Del Norte Mountains was already marked on my map https://caltopo.com/m/K2L8P as “near head of Big Aguja Canyon, Fowlkes’ Ranch” .
the total solar eclipse will be that day, but but you’ll need to be several hundred miles to the east to be in the path of totality. just something to consider, since you’ll have traveled all that way to Texas.