372 



Betulaceae 



1. Ostrya japonica Sarg. O. virginica var. japonica 



Maxim, ex Sarg.; O. japonica var. homochaeta Honda 



AsADA. Tree with pubescent and glandular-pilose young 

 branchlets; leaves rather thin, narrowly ovate or ovate-oblong, 

 7-12 cm. long, 3-5 cm. wide, acuminate to very acute with 

 irregular awn-tipped teeth, pubescent and glandular-pilose on 

 both sides or becoming glabrate except on nerves beneath, the 



lateral nerves of 9 to 13 pairs, the petioles 4-8 mm. long, 

 pubescent and glandular-pilose; fruiting aments narrowly 

 ovoid, nodding, pedunculate, the scales ovate-eUiptic, 13-17 

 mm. long, entire, acute, short-pubescent, connate and clasping 

 the nut below; nuts oblong-ovate, 5-6 mm. long, glabrous or 



with short hairs above. ^May-June. Hokkaido, Honshu, 



Shikoku, Kyushu. Korea and China. 



3. CORYLUS L. 



Hashibami Zoku 



Deciduous trees or shrubs; leaves alternate, simple, scattered-pilose, doubly toothed, petiolate, induplicate in bud, the stipules 

 caducous; staminate aments elongate, pendulous (naked in winter), the flowers naked, each scale with 4-8 axillary stamens, 

 die filaments bifid above, the anthers pilose at apex; pistillate aments capitate, the flowers paired in the axils of small 

 bracts, the perianth short; ovary 2-locular, the ovules 1 or 2 in each locule; styles 2, the stigma exserted; nuts rather large, en- 

 veloped by an involucre, the cotyledons thick, hypogeal. About 20 species, in the N. Hemisphere. 



lA. Involucre leaflike, deeply incised, not tubular, not bristly; leaves broadly obovate, obovate-rounded or nearly obversed deltoid. 



1. C. keterophylla 

 IB. Involucre connate and tubular above the nut, densely bristly; leaves obovate to broadly so 2. C. sieboldiana 



1. Corylus heterophylla Fisch. O-hashibami, Ohyo- 

 HASHiBAMi. Shrub or small tree, the branchlets pubescent 

 and glandular-pilose while young; leaves deltoid-obovate to 

 orbicular-obdeltoid, 5-12 cm. long and as wide, truncate and 

 abruptly acuminate, incised and doubly toothed, cordate, 

 pubescent above while young, with short spreading hairs be- 

 neath and loose ascending hairs on nerves, the petioles 5-20 

 mm. long, pubescent and glandular-pilose; nuts 1-3 in a 

 cluster, the involucre campanulate, 2.5-3.5 cm. long, puberu- 

 lent, glandular-pilose below, striate, deeply toothed on margin; 



nuts subglobose, about 1.5 cm. across. Honshu (centr. 



distr.). Korea, Manchuria, Ussuri, and Amur. 



Var. thunbergii Bl. C. heterophylla var. yezoensis Koidz.; 



C. yezoensis (Koidz.) Nakai Hashibami. Leaves ob- 



ovate-orbicular to broadly obovate, abruptly short-acuminate, 

 rarely glandular-pilose; involucres scarcely glandular-pilose. 

 Hokkaido, Honshu, Kyushu. 



2. Corylus sieboldiana Bl. C. rostrata var. sieboldiana 



(Bl.) Maxim.; C. rostrata var. mitis Maxim. Tsuno-ha- 



SHiBAMi. Large shrub with pubescent branches; leaves 



obovate to broadly so, 5-10 cm. long, abruptly acuminate, ob- 



soletely incised and acutely serrulate, rounded or rarely shal- 

 lowly cordate at base, often with a large brown-purple blotch 

 on the center above, glabrous to slightly appressed-pilose on 

 upper side, becoming yellowish brown when dry and loosely 

 ascending-pilose on the nerves beneath, the petioles 1-1.5 cm. 

 long, pubescent; nuts 1-3 in a cluster, short-conical, 6-8 mm. 

 long, the involucre tubular, 1.5-5 cm. long, narrowed above 

 the nut, shortly lobed or deeply dentate, puberulent and 

 densely bristly-hairy. Hokkaido, Honshu, Shikoku, Kyu- 

 shu. 



Var. brevirostris C. K. Schn. C. brevirostris (C. K. Schn.) 

 Miyabe. Tokkuri-hashibami. A phase with short in- 

 volucres 1-2 cm. long. Occurs with the typical phase. 



Korea. 



Var. mandshurica (Maxim.) C. K. Schn. C. mandshurica 



Maxim.; C. rostrata var. mandshurica (Maxim.) Kegel 



O-tsuno-hashibami. Leaves relatively large, distincdy in- 

 cised, often cordate, pale green beneath, rather thin; invol- 

 ucres gradually narrowed above, with spreading brisdelike 



hairs; nuts larger. Hokkaido, Honshu (n. and centr. 



distr.) . Korea, Manchuria, Amur, and Ussuri. 



4. BETULA L. Shira-kamba Zoku 



Deciduous shrubs and trees; leaves petiolate, usually ovate, serrate-toothed, rarely incised, penninerved, the stipules deciduous; 

 staminate aments elongate, pendulous (naked in winter), the scales usually 3-flowered in the axils, the bracteoles 2, adnate to 

 the scale; perianth 4-parted; stamens 2, the filaments 2-fid above; pistillate aments short, sometimes cylindric, 3-flowered in the 

 axils of bracts, the perianth absent; nuts usually wing-margined; deciduous with the scales. About 40 species, in the tem- 

 perate and cold regions of the N. Hemisphere. 



lA. Fruiting aments 2-4, racemose, long-cylindric, (2-) 3-7 cm. long; leaves 8-14 cm. long, cordate 1. B. maximou/icziana 



IB. Fruiting aments solitary, globose to short-cylindric, 1.5-5 cm. long; leaves less than 10 cm. long. 



2 A. Leaves distinctly glaucous beneath; fruiting aments erect 2. B. corylifolia 



2B. Leaves pale green and not glaucous beneath. 



3A. Fruiting aments erect or pendulous, short-cylindric or oblong-cylLndric, the peduncles 3—12 mm. long. 



4A. Fruiting aments pendulous; bark white and smooth; leaves broadly deltoid-ovate to subdeltoid 3. B. platyphylla 



4B. Fruiting aments erect; bark brownish. 



5A. Leaves narrowly ovate-oblong to broadly ovate, dull above, with upward pointing teeth; petioles 5-15 mm. long. 

 6A. Trees; leaves 4-8 cm. long. 



7A. Midlobe of fruiting scales slightly shorter than the lateral lobes; leaves irregularly toothed, the lateral nerves 6- to 



8-paired; petioles 5-15 mm. long 4. B. davurica 



7B. Midlobe of fruiting scales longer than the lateral; leaves serrulate, the lateral nerves 9- to 18-paired; petioles 4-10 mm. 

 long. 



8A. Branchlets distinctly glandular; leaves with 9-10 pairs of lateral nerves 5. B. schmidtii 



8B. Branchlets scarcely glandular; leaves with 14 to 18 pairs of lateral nerves 6. B. chichibuensis 



