Species In Our
R. yungningense is in Subsection Lapponica This subsection contains more than 40 species, characterized by dwarf, small, erect, compact and even prostrate shrubs, many of which have small leaves and blue or purple flowers.
R. yungningense is named after the town of Yungning in southwest Sichuan in China near where it grows. R. yungningense was formerly known as R. glomerulatum, which means 'with small clusters'.
R. yungningense is a somewhat erect and compact shrub 1-4 feet high, with leaves 1/3 to 1 inch long, elliptic to oblong, dull green and densely scaly above, also densely scaly below with brown or cinnamon-red scales. The flowers are terminal with trusses of 4-6 flowers. The corolla is five-lobed, funnel-shaped and 1/2 inch in size; it can vary in color from deep purplish blue, pale rose purple, pale blue purple, or deep purplish red and a rare white. The plants are found on alpine slopes, in meadows, rhododendron scrub, stony moors and on cliffs and rocky areas from 11,000 to 14,000 feet on mountains east of the town of Yungning.
R. yungningense was first discovered by George Forrest in 1921 and again on his 1930-31 expedition. In 1932 R. glomerulatum was described from a plant grown by Lord Headfort at Kells, County Meath, Eire and raised from Forrest seed. The plant appeared identical in growth habit, height, leaves and flower color to R. yungningense, which it is now called.
Though I can find no listed horticultural hybrids of R. yungningense, there is a mention of a natural hybrid with R. rupicola mentioned by Cullen; Peter Cox, in his Smaller Rhododendrons lists several plants formerly regarded as species, but now classified as natural hybrids of R. yungningense. It seems to hybridize easily and would appear to be an interesting candidate to cross with some of the other blue and purple species in the Lapponica Subsection in our quest for hardy blues.
I acquired my plant of R. yungningense several years ago after it had been used in our flower show exhibition. It came from A Sandy Rhododendron on the West Coast and was listed as R. glomerulatum. Though the winters since I have owned it have not been really harsh enough to test its hardiness, it has done well for me. Greer rates it -15°F. My plant is now 18 inches tall, has been well budded each year with flowers in May, a pleasant pale blue with no purple. It makes a good plant for the front of the border.
Elizabeth Carlhian, Concord, MA