242 JOURNAL OF THE ARNOLD ARBORETUM [vol. iv 



Hydrangea opuloides var. Thunbergii Makino in Tokyo Bot. Mag. xxvi. 389 



(1912). 

 Hydrangea cyanea Hort. apud Bean, Trees & Shrubs Brit. Isl. i. 630 (1914). 

 Ili/drangea opuloides var. serrata Rehder in Bailey, Stand. Cycl. Hort. in. 1621 



(1915). 



Hydrangea persicifolia Hort. ex Herb. Arnold Arboretum. 

 Japan. Kyushu: prov. Satsuma, Kirishima, alt. 100-1000 m., Z. Tashiro, 

 October, 1917; Shikoku, prov. Tosa, Shiraga-vama, alt. 1100 m., E. H. Wilson, 

 No. 1720, November 22, 1914; Nanokawa, K. Watanabe, July, 1888 (Herb. Gray). 

 Hondo: prov. Settsu, Arima, A. Henry (No. m. 83); prov. Yamashiro, Kyoto, 

 June 24, 1911; prov. Shinano, Otake-gawa, alt. 1000 m., E. H. Wilson, No. 7767, 

 November 1, 1914; Norikura, U. Faurie, No. 6859, August 30, 1905; Ogawa, 

 J. G. Jack, September 1, 1905; prov. Sagami, Komagatake, alt. 2000 m., U. Faurie, 

 No. 6862, July, 1905; Miyanoshita, C. S. Sargent, Aug it 25, 1892; same locality, 

 Drs. Fred & Charlotte Baker, June 18, 1914, Ilakone, C. Maximowicz, 1862 (Herb. 

 Gray); prov. Mu i, Mitsumine-san, E. H. Wilson, No. 6963, June 8, 1914; 

 same locality, June 24, 1911; Mt. Buko, A'. Sakurai, June 25, 1911; prov. Kai, 

 Jizo-g;itake, U. Faurie, July, 1903; prov. Kozuke, Karuizawa, alt. 1000 m., E. H. 

 Wilson, Nos. 741' 7 August 1, 1914; prov. Shimotsuke, Nikko region, alt. 



1600-2000 m., I II. II m, June 28, 1914; Lake Chuzenji, J. G. Jaek, August 10 

 ;ind 12, 1905. Withi t locality ex Herb. Lugd. Batav. as Hydrangea Buergeri and 

 //. japonica (Herb. Gr: 



Korea: Quelpaert Island, alt. 600 m., E. II. Wilson, No. 9402, October 30, 1917; 

 same place and collector, No. 9402a November 6, 1917; same locality, U. Faurie, 

 Nos. 3f , 359, 1653, Oct» >er, 1906, July, 1907; me locality, E. Taquet, No. 4240, 

 July 15, 1910. 



Cui \ted: Arnold Arboretum, July 20, 1S90, July 9, 1897, Nos. 519, 519-1, 

 3269; July 6, 19 S, E. II. Wilson, No. 7621; Kew Gardens, G. Nicholson, No. 2900, 

 Julv 13, 1882; Hort. Muskau, September 15, 1895, ex Herb. Zabel, No. 1881; 

 Botanic Gar hi, Sapporo, Hokkaido, E. II. Wilson, No. 7303, July 29, 1914; 

 same garden, S irimoto, September 7, 1903 (Herb. Gray). 



Shrub 1-2.5 m. tall (usually 1 1.5 m.) with erect slender stems, glabrous 

 or pubescent the first year, clothed with thin brown-purple scaling bark. 

 Leaves membranous, dull dark green, lanceolate or elliptic to ovate, rarely 

 broadest above the middle, without petiole 5-10 cm. long, 1.5-5 cm. wide, 

 acuminate; the base cuneate, rarely abruptly so, sometimes attenuate and 

 oblique, finely or coarsely serrate, often entire at base; the teeth terminat- 

 ing in gland-tipped mucro, sparsely clothed with appressed soft pubescence 

 on both surfaces, with small axillary tufts of curled hairs on the lower 



surface; midrib with short curled hairs sometimes on upper surface only; 

 petiole 1 2.5 cm. (sometimes 5 cm.) long, usually slender. Flowers blue 

 or white in flat or slightly convex corymbs, 5-10 cm. across with 4 or 5 

 white, blue or pinkish petaloid, orbicular, ovate or lanceolate, rounded, 

 obtuse or more rarely acute sepals. Capsule thin-walled, ovoid, sub- 

 globose, 2-4 mm. long, on a slender pedicel and tipped by 3 short diverging 

 styles. 



This is a common woodland plant on the mountains from the extreme 

 south of Japan to southern Hokkaido; it is also plentiful on the Korean 

 island of Quelpaert and on the mainland as far north at least as Chiri-san. 

 At the northern limits of this species the plant is found at sea-level but 

 always in cool situatioi . It loves woodland soil and shade and it is 

 only at high altitude- and t it northern limits that it grows in open 

 places. The plant varic in the size, shape and dentation of the 



