JARS v46n4 - An Unusual Rhododendron occidentale Find

An Unusual Rhododendron occidentale Find
Mike Oliver
Portland, Oregon
Frank Mossman
Vancouver, Washington

The past few years we have renewed the R. occidentale trips that Britt Smith and Frank Mossman regularly took to southern Oregon and northern California to find interesting forms of the western azalea, R. occidentale , in the wild. Last spring, accompanied by Eleanor and Art Stubbs, we found a very interesting form with no petals! A representative truss consists of 15 pistils and 70 stamens. The plant is six feet high and leggy, similar in general habit and leaf to other plants on the hillside. The plant is in a large patch of R. occidentale a few miles west of O'Brien, Ore. This area is sloping and wet, being fed by springs. R. occidentale prospers in such sunny, wet areas. Nearby Darlingtonia grows in profusion along the main paths of the runoff from the springs.

Doris Mossman named this form 'Bare Bottoms'. The photograph shows a typical flower. All the trusses on the plant appeared identical, and there were no other unusual azaleas seen in the vicinity. This plant will be observed over the next few years to determine if the no-petal behavior is stable.

Apetaloid form of R. occidentale
Apetaloid form of R. occidentale.
Photo by Mike Oliver

A few miles away, on O'Brien Flats, the 'Miniskirt' form of R. occidentale was found 25 years ago by Britt Smith (1, 2, 3, 4). It has three-eighths inch corollas and small leaves on small caliper wood.

Howard Slonecker found an apetaloid R. occidentale , 'Pistil Packin' Mama', and nearby a form with tiny petals, 'Pistil Pete' (2, 4). Neither form has stamens. An apetaloid of another native American azalea R. calendulaceum named 'Cullowhee' was discovered several years ago in North Carolina (5, 6). In his excellent book, Kalmia The Laurel Book II , R. Jaynes describes an apetaloid form of mountain laurel, Kalmia latifolia (7).

This newly found form of R. occidentale is the first of its type reported for this species and adds to a group of apetaloid forms of similar ericaceous plants.

We are looking forward to comparing these oddities when displayed together. It leads one to consider a side show at a standard rhododendron show. You can almost hear the barker shout, "Come see the oddball azaleas, only fifty cents."

1.  ARS Quarterly Bulletin, 1968:3, p. 133.
2.  ARS Quarterly Bulletin, 1974:4, pp. 246-7.
3.  ARS Quarterly Bulletin, 1972:4, pp. 221-2.
4.  Galle, Fred, Azaleas , Portland, OR, 1985, p. 90.
5.  ARS Quarterly Bulletin, 1974:1, p. 46.
6.  'Castanea', Dept. of Biology. Western Carolina University, Cullowhee, NC, #38, p. 204, 1973.
7.  Jaynes, Richard A., Kalmia The Laurel Book II , Portland, OR, 1988, p. 34.

Frank Mossman has been studying R. occidentale for 27 years and has written numerous articles for the Journal, receiving The Gold Medal for his work.
Mike Oliver has been studying and collecting R. occidentale for seven years.