522 



ROSACEAE 



4. ARUNCUS Kostel. Yamabuki-shoma Zoku 



Dioecious perennial herbs; rhizomes short-creeping, stout; leaves radical and cauline, alternate, ternately compound, petioled, 

 toothed, exstipulate; inflorescence a terminal panicle of densely flowered, simple to again branched racemes, the bracts linear, 

 often pardy adnate to the pedicel; flowers small; calyx 5-toothed, the teeth valvate in bud; petals 5, small, spathulate, inserted 

 on the throat of the calyx-tube; stamens about 20; carpels usually 3, rarely more, free, die ovules many, pendulous; follicles 



coriaceous, ventrally dehiscent, the seeds scobiform, without endosperm. Few species in the cold temperate regions of the 



N. Hemisphere. 



1. Aruncus dioicus (Walt.) Fern. var. kamtschaticus 



(Maxim.) Hara. A. Sylvester var. \amtschaticiis Maxim.; A. 

 \amtschaticus (Maxim.) Rydb.; A. sylvester var. tomentosus 

 Koidz.; A. tomentosus (Koidz.) Koidz.; A. sylvester var. tenui- 

 jolius Nakai; A. sylvester var. amencanus Maxim, pro parte; 

 A. kyusianus Koidz.; A. dioicus var. tenuif alius (Nakai) Hara 



Yamabuki-shoma. Glabrous to sparingly pubescent 



coarse perennial herb with rather stout branching rhizomes; 

 stems 30-80 cm. long, with a few deciduous scales at base, 

 terete, few-leaved; leaves few, 2- or 3-ternate, the leaflets thinly 

 chartaceous, often lustrous, narrowly ovate to ovate-orbicular, 

 3-10 cm. long, 1-6 cm. wide, acuminate to caudate, incised 

 and toothed, sometimes pinnately lobed; inflorescence 10-30 

 cm. long, short-pubescent; flowers many, white, short-pedi- 

 celled; petals broadly spathulate, small; fruit pendulous on a 

 deflexed pedicel, the carpels lustrous, about 2.5 mm. long, the 



styles short, about 0.5 mm. long. June-Aug. Hokkaido, 



Honshu, Shikoku, Kyushu; rather common and variable. 



Kamchatka, Kuriles, Sakhalin, Ussuri, Manchuria, Korea, and 

 China. 



Var. insularis Hara. Shima-yamabuki-shoma. Petals 



larger, elliptic, about 1.2-1.5 mm. long, firm; calyx-lobes 



larger; style longer, about 0.8 mm. long. Izu Isls. 



(Oshima). 



Var. laciniatus (Hara) Hara. A. vulgaris var. laciniatus 



Hara Kireba-yamabuki-shoma. Leaflets deeply incised, 



ovate-lanceolate; petals in staminate flowers narrowly oblong, 

 2 mm. long. Hokkaido (s. Hidaka Prov.). 



Var. astilboides (Maxim.) Hara. Spiraea aruncus var. 

 astilboides Maxim.; A. astilboides Maxim.; A. sylvester var. 

 astilboides (Maxim.) Makino; A. vulgaris var. astilboides 



(Maxim.) Nemoto Miyama-yamabuki-shoma. Pedicels 



and follicles erect when mamre. High mountains; Honshu 



(Mount Hayachine in Rikuchu Prov.). 



Var. subrotundus (Tatew.) Hara. A. subrotundus Tatew.; 



A. sylvester var. subrotundus (Tatew.) Ohwi Apoi-yama- 



BUKi-SHOMA. Leaflets rather firm, ovate-orbicular to broadly 

 ovate, rounded with a short cusp at apex, acutely toothed; fruit 



pendulous on a deflexed pedicel. Hokkaido (Mount Apoi 



in Hidaka Prov.). 



5. RHODOTYPOS Sieb. & Zucc. 



Shiro-yamabuki Zoku 



Deciduous shrubs; leaves opposite, short-petioled, simple, penninerved, the stipules free, linear, hairy, membranous, pale green; 

 flowers solitary, terminal on short branches, large, white, short-pedicelled; calyx persistent, the tube short, the segments 4, spread- 

 ing, rather large, acutely toothed, bracts of the caliculus 4, small; petals 4, spreading, orbicular; stamens many; carpels 4; styles 

 filiform, glabrous; ovules 2 in each carpel; achenes 1-4, black, plump. A single species, in e. Asia. 



1. Rhodotypos scandens (Thunb.) Makino. Corchorus long; flowers 3-4 cm. across, on pedicels 7-20 mm. long; 



scandens Thunb.; Kerria tetrapetala Sieb.; R. tetrapetala 

 (Sieb.) Makino; R. \errioides Sieb. & Zucc. Shiro-yama- 

 buki. Shrub with spreading glabrous branches; leaves 

 membranous, ovate, 4-6 cm. long, 2-4 cm. wide, acuminate, 

 rounded at base, acutely double-toothed, more or less long- 

 appressed yellowish pubescent beneath, the petioles 2-3 mm. 



calyx and pedicels pubescent, the lobes narrowly ovate, 1-L5 

 cm. long, the bracts of the caliculus linear to lanceolate, 4-8 



mm. long; achenes 7-8 mm. long, ellipsoidal, glabrous. 



Apr.-May. Honshu (Chiigoku Distr.) ; often cultivated. 



Korea and China. 



6. KERRIA DC. 



Yamabuki Zoku 



Deciduous branched shrubs; leaves short-petioled, simple, alternate, the stipules linear, pale brownish; flowers pedicellate, 

 large, terminal and solitary on short branchlets, usually yellow; calyx persistent; petals 5, or many in a double-flowered cultivar; 

 stamens many; carpels 5-8, glabrous, the ovules solitary in each locule, the styles filiform; achenes ovate-globose, rather plump. 

 A single species, in China and Japan. 



1. Kerria japonica (Thunb.) DC. Rubus japonicus L.; 



Corchorus japonicus Thunb. Yamabuki. Much-branched 



shrub with slender, green, spreading, glabrous branches; leaves 

 membranous, ovate or narrowly so, 3-7 cm. long, 2-3.5 cm. 

 wide, long-acuminate, incised duplicate-toothed, vivid green, 

 paler beneath, nearly glabrous; flowers 2.5-5 cm. across; calyx 

 glabrous, the tube short, the segments broadly ovate to elliptic, 

 spreading, denticulate; petals ovate-orbicular, spreading; 

 achenes 4-5 mm. long. Apr.-May. Common in moun- 



tains; Hokkaido, Honshu, Shikoku, Kyushu. Several cultivars 

 are grown: Cv. Plena. K. japonica forma plena C. K. Schn. 



Flowers double. Cv. Stellata. K. japonica forma stellata 



(Makino) Ohwi; K. japonica var. stellata Makino Kiku- 



zaki-yamabuki. Flowers with more numerous petals than 

 in Cv. Plena. Cv. Albescens. K. japonica forma albes- 

 cens (Makino) Ohwi; K. japonica var. albescens Makino 



Shirobana-yamabuki. Flowers nearly white. 



