Notes and Comments Regarding the Rock Expedition Seedling Rhododendrons
Dr. Carl Heller
As a great and pleasant surprise, Dr. Joseph F. Rock visited the Rhododendron Show and Test Gardens at Portland, Oregon, May 2nd and 3rd. Because of the generous cooperation of members of the Society who have raised seedlings from the 1948 Rock expedition, we already had a modest, temporary planting of many of the species he collected in our "Rhododendron Bank." Dr. Rock commented favorably on the progress of these seedlings on the Island. He kindly answered, for two days on end, the numerous questions the members had concerning the method of collecting the seeds, the trials and tribulations concerning their shipment and told in fascinating detail of his escape from (and loss of) his home in Lichiang, Yunnan, China. (Lichiang was in the center of a local and independent communist uprising.)
Contrary to a previous report (Brydon, A.R.S. Rhododendron Bulletin), Dr. Rock did not first select and tag rhododendrons in flower in spring and return later in fall to collect seeds as he ordinarily would do. He explained he received confirmation that members of the American Rhododendron Society were underwriting his seed collecting expedition too late in the season to mark the flowering plants. He did see and note blooms on an occasional plant, however.
Dr. Rock was still grumbling good-naturedly about the incident of the seed bags. Only large cloth bags will do for collecting the seed capsules in the mist and rain. He had requested and specified the number, size, nature and time the bags were to reach him from Portland, since none could be purchased in China. His specific directions were carried out meticulously by the Society members and the bags were dispatched post-paid by air express. But when the time for collecting arrived, the bags had not made an appearance in Lichiang. It seemed that the expedition was doomed to abject failure at this juncture - until Dr. Rock contributed his own bed sheets and had his native help tear them up and make seed collecting bags from them. This solved the immediate problem, but this was not the end. Long after the seeds were sown in the United States, he received a summons to send for a crate of seed bags consigned to him and in storage at Hong Kong. Duty and storage costs for now worthless bags came to $50.00 cash.
Several of the seedling have bloomed and in a few instances a definitive identification has been possible. Among those reported to have flowered are:
No. 7. Lapponicum series. Several plants have bloomed including some in the "Rhododendron bank." They have varied from a clear bright dark yellow to pale creamy yellow. The bright yellow was exceptionally good. This has been tentatively identified as R. chryseum.
No. 43. Lapponicum series. This has foliage and habit similar to No. 7 and has been reported to be yellow. It too possibly is R. chryseum.
No. 188. Lapponicum series. Three distinct forms have appeared under this number. (These are not "rogues" in the sense of mix up in labels or seeds since arrival in Portland.) Each has very glaucous, very attractive blue foliage. The majority resemble the very finest blue foliage forms of R. impeditum. This group has a very dwarf, neat habit and blooms which resemble R. impeditum closely. They vary considerably in size and color. The color ranges from clear light blue, through darker blues, and lavender to ugly reddish blues. They bloom very profusely and over a long period of time. The tentative identification is R. litangense, but it could turn out to be R. impeditum, the difference between these two species is very, very slight.
A second form has larger and somewhat less blue leaves and grows a bit more vigorously. It has lavender blue flowers having scales on the outside of the corolla. This has been tentatively identified as R. verruculosum.
The third form has the tiniest leaves of any rhododendron I have encountered. Its habit is exceptionally dwarf and the shrubs are about the size and shape of a pin cushion. The plant in all its component parts is identical to the first group described and must therefore, be
R. litangense
or
R. impeditum
. However, the flowers are as large as on the regular
R. impeditum
. I wonder whether these few plants are not missing a half set of chromosomes, i.e. could they be haploids?
No. 127 Lapponicum series. In several gardens this has had yellow flowers and identified as
R. chryseum
and has been in no way superior to
R. chryseum
currently in cultivation. One plant, exhibited at the Rhododendron Show by Rudolph Henny, and now residing in the "Rhododendron Bank" had deep clear dark large purple flowers. Unfortunately it has not been further identified.
"Hippophaeoides from swampy places" has bloomed a sickly bluish pink. This seed was collected by Dr. Rock in 1947.
No. 5. Saluenense series. Two forms one with small shiny green leaves is probably
R. keleticum
. (No report of its having bloomed has been received). Another with larger dull gray-green leaves has been raised. The larger leaf plants have had exceptionally large two flowered blooms held high over the plant on pedicels two inches tall. They have been an attractive mauve color. These have been tentatively identified as
R. nitens
.
No. 58. Keleticum. The same two varieties noted under No. 5 appeared here also. One appears to be
R. keleticum
and the other
R. nitens
.
No. 15. Boothii series, affinity
R. xanthostephanum
. Robert Bovee reports this is a pale yellow.
No. 12. Glaucum series,
Brachyanthum
variety
hypoledidotum
was on display at the Cut-Truss show Memorial Day week-end in the exhibit of Mr. and Mrs. Yettick of St. Helens. It was a nodding attractive butter yellow. The flower was cup-shaped and quite small. These plants have a very attractive habit and foliage. There are several of these available for trading in the "Rhododendron Bank."
No. 93. Glaucum series,
Brachyanthum
variety
hypolepidotum
has similarly nice foliage and habit. The blooms, as reported by Mr. and Mrs. Yettick, are a paler yellow.
No. 53. Sanguineum species nova.
No. 54. Sanguineum species nova.
No. 44. Sanguineum series.
No. 45. Sanguineum series.
No. 62. Sanguineum series.
No. 64. Sanguineum series.
Each of these has bloomed. Bloom appears in late June or July and is black-crimson in color. There are 8 blooms in a truss for each of them except R. 64 which is 4-5 flowered. Each of these have been tentatively identified as
R. didymum
. It should be pointed out that the identification is tentative (i.e. made by amateurs) but for all practical purposes these plants are
R. didymum
. This has come as a crushing blow to the many members who gave such extra special care to the two "new species," not that the plants are not attractive, but such high hopes had been held for something unusual and exotic. It has occurred to several of us that there may still be two "species nova" as suggested by the Royal Botanic Gardens at Edinburgh. There may be a discrepancy between the herbarium specimen numbers and the seed numbers.
No. 18 Sanguineum series. To compensate for this disappointment. Rudolph Henny reports that this is a flashy orange and very attractive. One plant only has bloomed.
No. 93 Repens, is pink.
No. 96 Oreotrephes
No. 165 Oreotrephes
"Deep pink tree" (1947)
Each has bloomed and is
R. oreotrephes
. The foliage is superior to most
oreotrephes
now in cultivation. Many of No. 165 are available in the "Bank."
R. 183 oleifolium has bloomed and is a most attractive pink and white. It is truly
R. oleifolium
and is totally different from what many of us are growing as
R. oleifolium
. The latter have turned out to be
R. hemitrichotum
or
R. racemosum
variety
oleifolium
in some instances.
It should be remembered that the flowers will most likely improve in color, quantity and size as the plants become older, and even the poorer ones should not be condemned as yet.
Dr. Rock explained the reason more than one species may appear under a given number. The collectors gather seed capsules on dwarf rhododendrons from not one, but from many different plants in order to obtain sufficient seed. The plants were not in bloom at the time. Seed from similar species could easily be taken.
Reports on the progress of your Rock seedlings will be appreciated.
The "Rhododendron Bank" is swelled with assets. We have many good plants to trade. For ground rules, see the April issue of the Bulletin.