The photo at right shows the corolla tube opened to show the stamens arranged at widely divergent levels in the flower of this species. The membrane between the calyx lobes of this species are typically non-keeled or only slightly keeled, while the similar long-leaf phlox has membranes between the calyx lobes that are strongly keeled and bulged outwards from the calyx.
Showy phlox is pretty perennial phlox with a shrubby base, with multiple stems which may rise from 15 to 40 cm high. Plants may be found winding up through the foliage of other medium height plants such as sagebrush) or found growing in the open by themselves. The herbage is glandular to glandular-hairy above and often glabrous below. The leaves are linear to broadly lanceolate, measuring up to 7 cm long and 1 cm wide. The leaves are opposite on the stems, and are widely spaced.
The inflorescence is a loose cyme. Individual corollas are pink to white, typically with notched lobes. The tube is 10 to 15 mm long, with the lobes an equal length. The calyx is about equal in length to the tube. The membranes between the calyx ribs are flat to slightly keeled. The style is very short (0.5-2 mm long) and is divided near the base into 3 linear stigmas which are longer than the style.
To my knowledge, no one is offering this plant for sale from nurseries, but it would be very attractive in the rockery or low shrubland garden to the east of the Cascades. Generally, this species and its cousin, the long-leaf phlox (See below.) do not do well west of the Cascades, even in good drainage because of the excessive moisture there.
Long-leaf Phlox: Phlox longifolia - Corolla lobes not notched at their tips. A long style is present, measuring from 6-15 mm long. Membranes between the calyx lobes strongly keeled and bulged outwards from the calyx.
Showy phlox is a wildflower of sagebrush, low, arid shrubland and open ponderosa pine forest habitats.
Showy phlox is found from the Okanogan valley of southern British Columbia, south to the Oregon side of the Columbia River. It is also found in southwestern Oregon and southward through the Sierra Nevada Mts into California. Eastward, its distribution extends to northern Idaho and western Montana.
In the Columbia River Gorge, it may be found between the elevations of 600'-3000' from Viento State Park in the west to the eastern end of the gorge.
-Showy phlox blooming at left on slopes above Canyon Creek, Klickitat Wildlife Area..........May 17, 2017. The photo at right shows a mass of showy phlox in bloom along paths between the Dalles Mountain Ranch and Crawford Oaks trailheads at Columbia Hills State Park......May 2, 2018.
-Showy phlox blooming on slopes above the Crawford Oaks trailhead at Columbia Hills Historical State Park.......May 5, 2018.
The photo above shows the widely spreading corolla lobes of the flowers of showy phlox as seen along forest road #82 just below spur road #190 on the southeastern side of Mt. Adams..........July 1, 2005. Note that the tips of the corolla lobes are notched which can help distinguish this species from long-leaf phlox (Phlox longifolia).