QBARS - v22n1 Japan Revisited

Japan Revisited
Frank Doleshy, Seattle, Wash.

On our 1967 trip to Japan Mrs. Doleshy and I visited several well-known Rhododendron areas and also some other places where we thought or hoped there might be Rhododendrons. These latter excursions were sometimes failures, sometimes productive. Often the day was saved by generous help from mountain climbers, the managers and maids of the inns, and various local residents who took the trouble to figure out our halting Japanese conversation.

We collected leaf specimens, felt the indumentum, examined the rock under the roots, took pictures whenever the highly unusual fall weather allowed this, and engaged in such other classical collecting activities as eating a little lunch or backing our U-drive car a hundred meters down the road so a log truck could squeeze past.

These observations and experiences will be the subject of an evening program at the Annual Meeting in Eugene. Meanwhile, however, our seeds will be distributed by the American Rhododendron Society Seed Exchange, and a listing may be useful to those who will soon decide what to order.

The plant names in this list conform with the 1965 English-language edition of Ohwi's Flora of Japan , with one exception: We use the new name R. metternichii var. kyomaruense , for the interesting populations described by Yamazaki in the Journal of Japanese Botany , 39:1. (This newly described variety includes the plants which Mr. Wada distributed under the tentative name of R. metternianum .)

This system of names, with some variations, has been used in almost all original studies during recent years. And, in early 1967, we were delighted to see that the Japanese Rhododendron specimens in the Harvard University Herbaria had been relabeled accordingly. The time has come, it seems, to recognize that a great deal has been learned about these plants in the middle third of the Twentieth Century, and that they can no longer be fitted comfortably into the traditional pigeon holes. We explained several of the changes in the account of our 1965 trip (A.R.S. Quarterly Bulletin , July, 1966), but a brief summary may be helpful.

R. chrysanthum , a name popularized as a result of incomplete research, is replaced by the correct R. aureum . And R. fauriei is considered, at most, to be a variety of R. brachycarpum .

R. degronianum is dropped in favor of R. metternichii var. pentamerum , but this latter name does not include all the phases of R. metternichii with 5-part flowers. Populations with thin indumentum and an open habit constitute the new R. metternichii var. kyomaruense . Also, the former R. yakushimanum is called R. metternichii var. yakushimanum (although there is some doubt that it should even be regarded as a separate variety).

The remainder of R. metternichii is treated as two varieties, the richly indumented var. metternichii and the thinly-indumented open-growing var. hondoense .

The following list includes all rhododendrons from which we collected seed in 1967 and these will be available through the Seed Exchange unless otherwise noted.

Rhododendron Species Distribution in Japan

Seed Collections

No. 21, R. metternichii var. hondoense (or possibly a natural intermediate between var. hondoense and var. kyomaruense) . October 9; above Omagawa Dam on Oi River tributary, ca. 5 kilometers from Sumatakyo Spa, Shizuoka Prefecture. Lat. 35°09'N., Long. 138°04'E. Elev. 1100 meters. Open habit, free-flowering, with large trusses. Indumentum thin, plastered, near-white to pale orange-buff, with somewhat metallic luster. This population in the southern Akaishi Range was apparently little-known outside the local area.

No. 22, R. metternichii var. kyomaruense . October 11; N. side of Jokoji Mtn., in Tenryu River drainage, Shizuoka Prefecture. Lat. 35°09'N., Long. 137°56'E. Elev. 900 m. Here or nearby, Yamazaki obtained the type specimen of this new variety on May 16, 1961. Very erect and open in 70% shade; denser in sunny spots. Free-flowering, often with 11-12 flowers per truss; said to be attractive. Indumentum thin to the point of being little more than a whitish-buff coloration. Mr. Wada kindly arranged to have us guided to this remote location by Mr. T. Amano, from nearby Yamazumi Village.

No. 23, probably R. keiskei . Growing with No. 22. Seed insufficient for general distribution, but see No. 39.

Nos. 26 and 27, R. japonicum . October 15; slopes of Mt. Nyugasa, S. of Lk. Suwa in Nagano Prefecture. Lat. 35°54'N., Long. 138°10'E. Elev. 1850 m. No. 26 is from plants with white leaf undersurface but unfortunately too small a collection for distribution. However, this fairly common variant (sometimes called the "glaucophyllum" cultivar) will probably be produced by some of the seed in the more plentiful No. 27 collection.

No. 28, R. brachycarpum . October 16; Yokodake, in Yatsugatake Range, Nagano Prefecture. Approx. Lat. 36° 05'N., Long. 138°19'E. Elev. 2300 m. Interesting form with no indumentum; dwarf at this high elevation.

No. 32, unidentified Azalea, possibly R. weyrichii October 27; Fukue-shima, the westernmost of the subtropical islands in the Goto Archipelago, Nagasaki Prefecture. Lat. 32°39'N., Long. 128°44'E. Elev. 100-140 m. This plant probably tolerates heat but lacks hardiness; should be ordered only by members in south Atlantic or Gulf areas or Japan. A gratifying find, because our Japanese friends had been amused at our plan to go to this island.

No. 35, R. metternichii var. metternichii . October 29; Shakutake (mtn.), on boundary of Oita and Fukuoka Prefectures. Lat. 33°11'N., Long. 130°53'E. Elev. 1210-1220 m. Fairly heavy indumentum; leaves somewhat domed and recurved; slight traces of top-surface hairs. Recommended for collection by a nurseryman who met with us when we visited Mr. Kunishige, of the Kurume Branch, Horticultural Research Station. The flowers, he said, are deeper-colored than those found on Mt. Hiko and other more northern points in the Kyushu volcanic area.

No. 37, R. kiusianum . October 31; Mt. Tsurumi, above Beppu in Oita Prefecture. Lat. 33°17'N., Long. 131°26'E. Elev. 1360 m. One of several isolated populations on Kyushu mountain tops. Seed ripe enough to shake off directly.

No. 38, R. metternichii var. metternichii , November 1; gully on side of Mimatayama, one of the Mt. Kuju peaks, Oita Prefecture. Approx. Lat. 33°08'N., Long. 131°11'E. Elev. 1300 m. Leaves similar to No. 35 but more shiny on top and slightly narrower. Also the effect of aging on indumentum color is more obvious; pale on current year's leaves, deep orange buff on last year's, and dull on 3 year-old. 12-14 flowers in some trusses. This was recommended as a desirable population by Mr. Wada and his friends, also by the Kurume nurseryman.

No. 39, R. keiskei . November 4; summit ridge of Mt. Ichibusa, boundary of Kumamoto and Miyazaki Prefectures, Lat. 32°18'N., Long. 131°06'E. Elev. 1700-1710 m. The only evergreen Rhododendron found growing on the sandstone and shale of this summit.

Nos. 40, 41 and 42. R. metternichii var. metternichii . November 5; vicinity of Shiromizutaki, Mt. Ichibusa area, Kumamoto Prefecture. Lat. 32°23'N., Long. 131°03'E. Elev. 800-950 m. On a NW spur of the granite which supports a rich flora on the lower slopes of Mt. Ichibusa but which does not extend to the summit. Possibly the southernmost natural population of R. metternichii var. metternichii . Leaves similar to Nos. 35 and 38 but more distinctly broad toward tip and with a greater tendency to be arched upward in center (i.e., domed). Leaves often retained 4 years. Capsules the largest seen, often in trusses of 10, and the anatomy of the capsules indicates an unusual degree of genetic uniformity. Protected by the rugged farmer-foresters in the tiny valley below, who extend their welcome to non-destructive collectors only. No. 41 is the main collection, elev. 950 m. No. 40 (insufficient for general distribution) is from one outlying plant at 800 m. No. 42 was picked by a farmer from a beautiful specimen transplanted to his garden. Ignoring the cloudburst, he refused to accept the idea of my leaving without all seed from this plant, probably selected for size of flowers.

No. 43, R. kiusianum . November 7; Mt. Karakuni, boundary of Kagoshima and Miyazaki Prefectures. Lat. 31°56' N., Long. 130°51'E. Elev. 1550 m. Same population as our No. 8 of 1965, but 300 m. higher. Seed again ripe enough to shake off directly.

In conclusion it is essential to comment on the A.R.S. Seed Exchange. This splendid arm of the Society makes it possible for a member to go out and collect in the wild with no worries about coming back to face a host of distribution problems and special requests. Indeed, the existence of the Seed Exchange has had some part in our decision to make these collecting trips to Japan.