(2006)  
 
Miyako-Teriha-No-Ibara (Shiny Leaved Field Briar from the Capital (Kyoto))
R. x momiyamae H. Ohba
Flora of Japan: 177 (2001)
Estimated parentage: R. luciae x R. paniculigera

(2006)  
 
Mori-Ibara (Forest Briar) R. onoei Makino var. hakonensis (Franch. et Sav.) H. Ohba syn. =R. jasminoides Koidz. [note also that another variety of R. onoei has this same synonym]
J. Jap. Bot. 75:161 (2000)
Distribution: Mountainous areas, mainly chestnut ranges, in Honshu (the Kanto district and further west), Shikoku, and Kyushu. No distribution on the Japan Sea side of the Archipelago.

R. onoei var. hakonensis grows naturally in mountainous areas on the Pacific side of Honshu, and in Shikoku and Kyushu. It has a good shade tolerance in woody areas. ... Though its single white flowers, about 2.5 cm across also resemble those of R. multiflora, they are not borne in large clusters in a natural environment, just one or two of them coming at the end of the stem. It produces long, thick peduncles with glandular hairs, and bears oval hips 7 to 12 mm across.

(2006)  Includes photo(s).
 
No-Ibara (Field Briar) R. multiflora Thunb. var. multiflora (syn. =R. polyantha Siebold et Zucc.)
Murray. Syst. Veg. ed. 14:474 (1784)
Distribution: SW-Hokkaido, Honshu, Shikoku, and Kyushu
R. multiflora grows naturally in many parts of Japan. Among the white-flowered wild roses growing in this country, only this rose has no pubescence on the surface of its united styles of pistils, so it is easy to determine its identity if we examine the flower with a magnifying glass. As its epithet indicates, the feature of R. multiflora is its big panicles with many flowers. However, there are a considerable number of local variations. In general, those found in northern areas, especially those in the Tohoku district on the Sea of Japan side, bear large flowers and inflorescences, which gradually become smaller in size as we come down to southern areas. The average size of the flower is between 1.8 and 2.3 cm across. Even smaller flowers we find in southern areas give off a wonderful sweet fragrance...
This is the rose famous for the roles it played as the ancestor of many cultivated roses, such as Multiflora Ramblers, Polyanthas, and Floribundas. It is also very familiar to us as commonly used rootstock in Japan. Fruits of R. multiflora are called 'Ei-jitsu', and have been used in traditional Chinese medicine for their strong diuretic effects.

(2006)  
 
Oo-Sakura-Bara (Large Cherry Rose) R. x pulcherrima Koidz.
Bot. Mag. Tokyo 31:128 (1917)
Estimated parentage: R. multiflora x R. onoei var. oligantha

(2006)  Includes photo(s).
 
Oo-Takane-Bara (Large High Mountain Rose) R. acicularis Lindl.
Ros. Monogr.: 44, t.8 (1820)
Distribution: Hokkaido, Northern Honshu
This is one of the "circumboreal plants" distributed widely in almost all the areas of high latitude in the northern hemisphere. In Japan, it is found in Hokkaido and northern parts of Honshu. The colour of the flower ranges from pale pink to violet carmine, but it is not clear whether this difference in colour is to be attributed to individual variations or to environmental effects. The flower is normally 4 to 5 cm across but the author has seen a large one, ca. 8 cm across, by a small stream in NE-Hokkaido. On the Okhotsk Sea coast of NE-Hokkaido, this rose also grows in swamp lands close by the seashore, and in the Tohoku district of Honshu Island, the author saw it growing in some particular places cooled by gap wind from underground on debris slopes. The fruit, obovate in shape, is about 2 cm long.

(2006)  
 
Ryukyu-Teriha-No-Ibara (Shiny Leaved Field Briar from Ryukyu)
R. luciae Rochebr. et Franch. ex Crép. f. glandulifera (Koidz.) H. Ohba (syn. =R. wichuraiana Crép. var. glandulifera (Koidz.) Honda)
Flora of Japan: 172 (2001)
Distribution: Southern Kyushu and Okinawa (Ryukyu) Islands
This is a kind of local variation of R. luciae (= R. wichuraiana) with thick glandular hairs on its inflorescence and calyx, found in southern parts of Japan. One of the selected varieties from Yakushima Island flowers remontantly, and in autumn, white flowers and red fruits display a beautiful colour combination

(2006)  Includes photo(s).
 
Sansho-Bara (Japanese Pepper (Zanthoxylum piperitum) Rose) R. hirtula (Regel) Nakai
Bot. Mag. Tokyo 34:14 (1920)
Distribution: Central Honshu
R. hirtula is found in the mountains between the chestnut zone and the beech zone in the Fuji-Hakone areas of central Japan. This is a deciduous tree which grows pretty large for a rose. The trees the author saw were about five metres tall. As the name suggests, this rose has leaves which look like those of the Japanese Pepper tree, and gives pale pink flowers 5 to 6 cm across during the rainy season in early summer. Its hips, covered with sharp prickles, look just like small chestnut burrs. In Autumn, when the hips ripen, a rich sweet scent like strong vintage liqueur fills the air under the tree.
It is a sort of mystery why this rose grows naturally in extremely limited places in the Fuji-Hakone areas. A fossil of "Akashi Sansho-Bara" (Rosa akashiensis Miki), found in a stratum near Kobe, is very famous, but needless to say, this species is now extinct.

(2006)  
 
"Shonosuke-Bara" (R. multiflora var. watsoniana (Crép.) Matsum.)

(2006)  
 
Takane-Bara (High Mountain Rose) R. nipponensis Crép. (syn. =R. acicularis Lindl. var. nipponensis Crép.)
Bull. Soc. Roy. Bot. Belgique 14:7 (1875)
Distribution: Honshu, Shikoku
'Nippon' means 'Japan' in Japanese, and R. nipponensis is an endemic species, which is seen in high mountains in central areas of Honshu and in Shikoku, usually on forest margins or in craggy places in conifer zones and Dwarf Siberian Pine (Pinus pumila) zones. This rose closely resembles R. acicularis, but it is smaller in size, and the leaf is totally different. The leaf of this rose has 7 to 9 leaflets, while that of R. acicularis has 5 to 7. Its lateral leaflets are roundish while those of R. acicularis are oblong. Also the margin of its leaflets is finely toothed unlike that of R. acicularis, which is crenated.
The flower is 3 to 4 cm across, and looks more delicate than that of R. acicularis....

(2006)  
 
Teriha-Ko-Hamanashi (Shiny Leaved Small Shore Pear)
R. luciae Rochebr. et Franch. ex Crép. x R. rugosa Thunb.
Estimated parentage: R. luciae x R. rugosa