Previous Next




Species In Our Midst
Rhododendron pseudochrysanthum

by Elizabeth Carlhian

Rhododendron pseudochrysanthum 'CSRG'
Picture by S & J Perkins
Rhododendron pseudochrysanthum 'CSRG' in Salem, NH

Rhododendron pseudochrysanthum

R. pseudochrysanthum is an elepidote (non-scaly) species of Genus Rhododendron, Subgenus Hymenanthes. Under the Edinburgh revision it is placed in Section Maculifera. These are Asian plants, and R. pseudochrysanthum is native to Taiwan (Formosa) where it is found on gravelly slopes and valleys in the mountains at elevations of 6000-13000 feet, often above tree line.

R. pseudochrysanthum was described by Hayata in 1908. Seed was collected by the E. H. Wilson, Arnold Arboretum-sponsored expedition to Taiwan from 1917 - 1919, with collectors' number 10928. The plant was first introduced by Patrick in 1972, as RV 72003.

R. pseudochrysanthum varies considerably in size and habit of growth from 1 to 10 feet high with a somewhat compact shape. The leaves, almost always described as rigid, are ovate, elliptic or oblong-lanceolate and usually with re-curved margins, as long as broad, with an upper surface glabrous (hairless) when mature, and dark green. The under surface is pale green. Young leaves are floccose (with loose-tufted soft wool) with long hairs.

The inflorescence, a lax truss in mid-spring of from 5 to 20 flowers, start as pink buds and open white or white, flushed pink, with deeper pink lines on the outside and flecks of crimson on the inside of the campanulate (bell-shaped) corolla. Individual flowers are 2 inches long. The ovary is densely stipitate (having a stalk), glandular and the style glabrous. The capsule is oblong or oblong-oval. Several writers cite the slow growth and the fact that the dwarf forms may take years to bloom.

R. pseudochrysanthum is not much grown on the East Coast. I do not have it but several of my friends in Concord, MA have small plants grown from seed. The Rhododendron Species Foundation lists the Exbury form, which it rates to -10°F (-23°C), as does Greer who lists four different forms:

  • Ben Nelson's form with longer leaves and silvery tomentum (dense woolly hairs on all parts except leaves)
  • Dwarf form with small leaves often with red undersides
  • Exbury form with silver foliage, won an award of Merit in 1956
  • Sunningdale form has interesting buff-colored tomentum

But it is Peter Cox, who in his two books, The Smaller Rhododendrons, and The Dwarf Rhododendrons, gives the most comprehensive evaluation I could find.

  • "This excellent species is only now becoming popular and seems little known in America to date (1973). Habit and foliage are first rate and very distinct and the beautiful flowers are produced in quantity once the plant reaches a reasonable size."
                        The Dwarf Rhododendrons (p. 81-82)

  • "A superb species of great character and merit. Many forms are now cultivated. RV 72003 . . . is producing an astonishing variation in foliage and habit. . . . Beautiful in flower this species is now gaining the popularity it deserves."
                        The Smaller Rhododendrons (p. 159)

Cox goes on to warn that some forms are prone to leaf-tip browning probably caused by heat and drought. He also comments that the leaves are so tough that they resist weevil damage.

With these comments and the recommendation of the Rhododendron Species Foundation that, "This is a superb and easily grown garden plant which can be quite dwarf and slow growing depending on the clone", I think we should consider trying R. pseudochrysanthum in the East, always making sure it has excellent drainage and summer moisture.

Elizabeth Carlhian, Concord, MA

Home Schedule Activities Join