Small thicket of native trees* (at right) in a sea of mostly non-natives growing along the Van Winkle Expressway, not far from what was once the Spring Run Fish Hatchery. Growing with (at left) the also native Apocynum cannabinum var. glaberrimus (Dogbane Hemp). The encroaching non-native Russian Olive will try to shade, crowd out and ultimately likely eliminate the native species. *Crataegus rivularis (syn. Crataegus douglasii var. rivularis).Aug. 3, 2013, Murray, Salt Lake County, Utah, elev. 4,310 ft.Some of the earliest collections of this taxon in Utah and in the northern part of the state:John C. Frmont, May 24, 1844, Utah County, near Utah LakeSereno Watson, Wasatch Mtns. around 5,000 ft elev, and probably in Salt Lake County, May 1, 1869Marcus Jones, City Creek Canyon, July 25, 1879
Crataegus rivularis (syn. Crataegus douglasii var. rivularis), a locally native and important tree.Trees have been in bud at this location for the past week but flowers did not start to open until yesterday under cool, rainy conditions. The temperature when this picture was taken was 48 degrees F and skies were cloudy (but no wind and actually very pleasant). So this species does not need warm temperatures to trigger flowering. While flowering in the spring, it also waits for some amount of leaf growth before starting to flower. Flowers are not fragrant.This species grows in areas that are moist, edges of wet meadows and ponds, as well as along streams. Native to the western United States.While often reported as a small tree (10 to 12 ft.), in favorable places it can easily grow to be 25-30 ft or more. Forms thickets. While it occurs over a wide elevational range, it is mainly known in our area from valley and foothill habitats.This is an under appreciated and under utilized tree.April 27, 2014 Salt Lake County, Utah, elev. 4,340 ft.
