Wild Roses In Japan (website)
Azuma-Ibara (Eastland Briar) syn. =Oo-Fuji-Ibara (Large Fuji Briar) syn. =Yama-Teriha-No-Ibara (Mountain Shiny Leaved Field Briar)
R. onoei Makino var. oligantha (Franch. et Sav.) H. Ohba (syn. =R. luciae Franch. et Rochebr.)
J. Jap. Bot. 75:157 (2000)
Distribution: Downs and lower mountainous in Honshu (Miyagi Prefecture and further south, and Toyokawa, Aichi Prefecture and further east)
As the Japanese name "Yama-Teriha-No-Ibara" indicates, it has glossy leaves and is often confused with "Teriha-No-Ibara" (R. luciae). However, its leaflets are not as round as those of R. luciae. The tree shape also differs. Unlike R. luciae, which spreads sideways hugging the ground, this rose grows upwards, sometimes climbing up trees using its prickles, 2 to 3 metres tall, and sometimes hangs down a steep slope. While the number of leaflets is 7 to 9 for R. multiflora and R. luciae, 5 to 7 is normal for all the R. onoei varieties, including var. oligantha. The flowers are white, 2 to 2.5 cm across, and closely resemble those of R. multiflora. However, this rose has thick hairs on its styles, while R. multiflora has none.
Douryou-No-Ibara (Field Briar from Douryou) R. x pulcherrima Koidz. nothovar. kanaii H. Ohba
Flora of Japan: 177 (2001)
Estimated parentage: R. multiflora x R. onoei var. hakonensis
Fuji-Ibara (Fuji Briar) R. fujisanensis (Makino) Makino
Bot. Mag. Tokyo 27:151 (1913)
Distribution: High mountains in the central area of Honshu, and in Shikoku.
A large colony dominated by this rose can be seen around the peak of Mt. Mitsutouge in Yamanashi Prefecture near Mt. Fuji. This is a rose with thick main stems which often grow over 10 cm across and densely put forth small branches. Its leaflets are dark green, and roundish in shape. The flowers are white, 2.5 to 3.0 cm across, and are arranged in panicles. The number of the flowers in a panicle differs widely, ranging from one to 20.
Hama-Nasu (Shore Aubergine) syn. =Hama-Nashi (Shore Pear) R. rugosa Thunb.
Murray. Syst. Veg. ed. 14:473 (1784)
Distribution: Hokkaido, Honshu
R. rugosa is distributed in the northern parts of Japan, mainly in coastal areas. This is the prefectural flower of Hokkaido, and there are some famous sights featuring Rugosa flowers on this island. We can also see this rose in Honshu, north of Chiba Prefecture on the Pacific coast, and north of Shimane Prefecture on the Japan Sea coast. When we visit the south end of its natural habitat in Chiba Prefecture in Kuju-Kuri Town, we can find a small area dominated by R. rugosa under conservation by the town....
The author has seen naturally growing R. rugosa in many different places. In Sado Island in the Sea of Japan, she saw a bush growing by the sea as if clinging to the rocky beach. On a beach in Hokkaido facing the Okhotsk Sea, it was blooming on a sandy stretch swept by cold winds. A beach which is constantly sprayed with sea water would not allow even this rose to survive, but it does not seem to mind a harsh wind from the sea. The author saw this rose beautifully in bloom where few other plants were seen growing.
It is famous as an ancestral rose of Hybrid Rugosas in European countries, and for long years, Japanese people have enjoyed its sweet fragrance, and also used petals and fruits of this rose for sweet preserves. In Akita Prefecture, the bark and roots of R. rugosa are sources of important dyes for dying traditional fabrics called 'Akita Ki-Hachijo' (Checkered Yellow Cloth from Akita).
Kakayan-Bara (Cagayan Rose)
syn. = Yaeyama-No-Ibara (Field Briar from Yaeyama Islands)
R. bracteata J. C. Wendl.
Bot. Beob.: 50 (1798)
Distribution: Yaeyama Islands
This rose is found only in some of the Yaeyama Islands, which are located in the southern points of Japan, but also is distributed in lowlands of Taiwan and southern areas of China. The author saw it growing wild in grassland on Ishigaki Island.
In 1828, a drifting ship reached the coast of Cagayan, northern part of Luzon Island, Philippine. When the sailors came back to Japan two years later, the captain brought seeds of R. bracteata to Daisuke Baba, a samurai and a famous plant collector. It was the first record of this rose in Japan, and so it came to be called Kakayan-Bara.
It gives pretty large white flowers 5 to 7 cm across. Notched bracts just below the calyx tube are the distinctive feature of this rose. A famous descendant of this rose, ‘Mermaid’ (W. Paul, 1918) has bracts of the same shape, too. The author heard that R. bracteata comes in bloom in May in its natural habitats, but the one she planted in Chiba (near Tokyo) gives flowers sporadically from May to November.
This rose displays many charms: for example, eye-catching golden stamens, evergreen shiny foliage, and growth like climbing roses, but unfortunately, it has no tolerance to cold weather.
Karafuto-Ibara (Sakhalin Briar) R. davurica Pall. var. alpestris (Nakai) Kitag. (syn. = R. marretti H. Lév.)
Neo-Lin. Fl. Manshur.:382 (1979)
Distribution: Hokkaido, Central Honshu
R. davurica var. alpestris is found in grassland and on forest margins in Hokkaido, and in some limited areas of central Honshu: Gunma and Nagano Prefectures. The flowers of this rose closely resembles that of R. rugosa, though it is a little smaller (3 to 4 cm across). Two, three, or more flowers are borne at the terminal of a small cane. The tree grows pretty tall, some reaching 2 metres or more. Its distinctive features are purplish coloured stems and reddish bracts at the base of a peduncle. It gives globular or ovoid fruits ca. 12 mm across. Its flowering period in C-Honshu is the beginning of July. Its fragrance is spicy, too, but less sweet than that of R. rugosa.
Ko-Hamanasu (Small Shore Aubergine) syn. =Ko-Hamanashi (Small Shore Pear)
R. x iwara Siebold ex Regel
Index Sem. Hort. Petrop. 1861:53 (1861)
Estimated parentage: R. multiflora x R. rugosa
"Maikai" (R. maikwai Hara)
Mishima-No-Ibara (Field Briar from Mishima) R. x misimensis Nakai
J. Jap. Bot. 15:529 (1939)
Estimated parentage: R. luciae x R. multiflora
Miyako-Ibara (Capital (Kyoto) Briar) R. paniculigera (Makino ex Koidz.) Momiy.
Acta Phytotax. Geobot. 20:26 (1962)
Distribution: SW-Honshu (western parts of Shizuoka Prefecture, Niigata Prefecture, and further west), N-Shikoku, N-Kyushu
R. paniculigera also closely resembles R. multiflora, bearing a lot of white flowers (ca. 1.8 cm across, a bit smaller than those of R. multiflora) in large panicles. However its stems, petioles, and canes are thickly covered with glandular hairs, and its styles also have hairs. Its flowering period is a little later than that of R. multiflora.