Magazine  (Sep 2016)  Page(s) 226, tab 840.  Includes photo(s).
 
Rosa hirtula...[by] Hideaki Ohba...Rosa hirtula (Regel) Nakai, a species endemic to Japan, is illustrated. It occurs in central Honshu around Mt. Fuji and Hakoneand vicinity. Rosa hirtula is similar to Rosa roxburghii Tratt., particularly to the single-flowered form, f. normalis Rehder & E. H. Wils., and is distinguished by its tree habit, hairy rachis, and lanceolate to narrowly oblong leaflets with acuminate to acuminate-apex, serrulate margins, and hairy midvein on the lower surface. .....

Article (newsletter)  (Jul 2012)  Page(s) 45-46.  
 
R. hirtula (Fig.1. p. faint, slightly spicy and woody scent) ....
....the fragrances which the nine roses below give off were not so intense. They lacked highly fragrant components, and the amounts of the volatiles these roses emit were low: R. acicularis, R. nipponensis, R. fujisanensis, R. onoei var. hakonensis, R. onoei var. oligantha, R. paniculigera, R. luciae, R. luciae f. glandulifera and R. hirtula. ...
We have also detected 4-vinylanisol¹⁵⁾ and 4- vinylphenol in the faint fragrance of R. hirtula. These two substances are known to be unique components of the Myrrh fragrance in some roses. ¹⁶⁾. Similar components have been found in the fragrance of R. arvensis (Table 3).

Article (magazine)  (2007)  Page(s) 370, fig. 1.  
 
R. roxburghii var. hirtula typical ploidy 2x

Website/Catalog  (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.

Book  (2006)  Page(s) 121-122.  Includes photo(s).
 
Sansho-Bara (Japanese Pepper (Zanthoxylum piperitum) Rose) R. hirtula (Regel) Nakai
Same text as on website

Article (magazine)  (2001)  Page(s) 393.  
 
R. roxburghii Tratt. var. hirtula Rehd. et Wils Ploidy 2x
Pollen fertility 98.6%
Selfed Fruit set 0%

Article (magazine)  (2000)  Page(s) 603.  
 
R. roxburghiin hirtula is recognized by some authors as species R. hirtula, whereas others identify it as a variety of R. roxburghiin. In this study, we detected polymorphisms not only on recognition sites of restriction enzymes but also on the length of amplified DNA by PCR (data not shown) between R. roxburghiin and R. roxburghiin hirtula. We propose that the two species be separated, based on the difference in their cpDNA.

Book  (1988)  Page(s) 168.  
 
R. roxburghii Tratt. var. hirtula Rehd. & Wils., PLATYRHODON, Japan, northern China, 1862, light pink, single, medium size, bushy, branched, 1.5-3 m, light-medium green small-medium matte-glossy foliage, 13-15 leaflets, green medium size matte prickly fruit, upright persistent short sepals

Book  (1965)  Page(s) 541.  
 
8. Rosa hirtula (Regel) Nakai. R. microphylla var. hirtula Regel; R. roxburghii var. hirtula (Regel) Rehd. & Wils. - Sansho-ibara. Large, much-branched shrub with much-flattened stipular prickles; stipules entire, glandular on margin, the free portion linear-lanceolate; leaflets 9-19, ovate-oblong or oblong, 10-25 mm. long, 5-15 mm. wide, acute, serrulate with short-awned acute teeth, nearly glabrous on upper side, paler and prominently pubescent especially on mid-rib beneath, the petioles and rachis short-pubescent; flowers solitary, terminal, pale pinkish, 5-6 cm. across, the pedicels stout, short, with needlelike prickles; calyx with densely prickly mbe, the lobes broadly elliptic, often with a small appendage near base; fruit globose, about 2 cm. across. - June. Honshu (Sagami, Kai, and Suruga Prov.).

Book  (1916)  Page(s) 320.  
 
Rosa Roxburghii var. hirtula Rehder & Wilson
[described primarily for its distinctions from R. roxburghii f. normalis, which has single flowers but lacks pubescence on the foliage]:
Its [R. Roxburghii f. normalis] ...leaflets and less sharply acute serratures and the absence of pubescence distinguish it from the Japanese R. Roxburghii var. hirtula Rehder & Wilson...It is this Japanese variety with single flowers which is in cultivation and which is figured by Hooker f. as R. microphylla... This var. hirtula is spontaneous in central Hondo, and Wilson has collected it at 1000 m alt. on the northern slopes of Fuji-san, Japan.