370 Juglandaceae; Betulaceae 



brown pubescent at first, soon glabrous except in the axils of mm. long, glabrous, obtriangular inclusive of the wing; 



the nerves beneath; aments few to several at the summit of staminate aments borne laterally below the pistillate. June- 



the young branchlets, erect, the terminal aments pistillate, July. Mountains; Honshu, Shikoku, Kyushu. Korea, 



3-4 cm. long, 2-3 cm. across, ellipsoidal, with dark brown, China, and Formosa, 

 linear-lanceolate, coriaceous, acuminate scales; fruit about 5 



2. PTEROCARYA Kunth Sawagurumi Zoku 



Deciduous monoecious trees; leaves alternate, pinnate, without stipules; flowers unisexual, on pendulous aments, the staminate 

 with 2 bracteoles adnate to the bract, the perianth 1- to 4-parted, the stamens 6-18; pistillate flowers with 2 bracteoles at base, 

 the perianth adnate to the ovary, the limb free, shortly 4-lobed; style short, bifid; fruit rather small, 2-winged; seed 4-locular at 

 base; cotyledons 4-lobed, green, epigeal. About 10 species, chiefly in China, 1 species in Japan, 1 in Asia Minor. 



1. Pterocarya rhoifolia Sieb. & Zucc. Sawagurumi. nate aments short-pedunculate; stamens 10; pistillate aments 



Tree; branches rather thick, terete, the branchlets short-pubes- pedunculate, very loosely flowered in the axils of scales, 



cent or nearly glabrous; leaves large, clustered on the upper elongate after anthesis, 20-30 cm. long in fruit; nut conical, 



part of branchlets, petiolate, imparipinnate, the leaflets 11-21, about 8 mm. long, 12-18 mm. wide inclusive of the winglike, 



ovate-oblong to lanceolate or broadly oblanceolate, 6-12 cm. obtusely toothed bracteoles. ^May. Valleys in mountains; 



long, 1.5-4 cm. wide, acuminate, serrulate, with yellowish Hokkaido, Honshu, Shikoku, Kyushu; rather common, 

 sessile glands and brown pubescence in axils beneath; stami- 



3. JUGLANS L. Kurumi Zoku 



Deciduous trees or rarely shrubs; leaves alternate, imparipinnate, foetid, without stipules, the leaflets opposite, entire or ser- 

 rate; staminate aments axillary and pendulous, elongate; flowers in the axils of scales, with 2 bracteoles, the perianth segments 

 1-4; stamens 3-40; pistillate aments terminal, loosely few to rather many flowered; flowers with a 3-lobed involucre consisting 

 of a bract and 2 bracteoles, the perianth 4-lobed; style bifid, the stigma pinnate; nut large, drupelike, indehiscent, incompletely 



2- or 4-locular, with a ligneous wall; cotyledons 2- to 4-lobed, retained within the nut in germination. About 15 species, in 



the temperate regions of the N. Hemisphere. 



1. Juglans ailanthifolia Carr. /. sieboldiana Maxim., Var. cordiformis (Maxim.) Rehd. /. cordiformis Maxim., 



non Goeppert; /. allardiana Dode; /. coarctata Dode; /. lavallei non Wangenh.; /. subcordiformis Dode Himegurumi. 



Dode; /. sachalinensis (Miyabe & Kudo) Komar.; /. tnirabunda Nut cordate or cordate-ovoid, rather depressed, the shell rela- 



Koidz. Onigurumi. Tall erect tree; branches grayish lively thin, nearly smooth, with a shallow groove on each 



brown, densely glandular-pubescent when young; leaves large, side. Cultivated. 



petiolate, the leaflets 9-21, ovate-oblong, 8-12 cm. long, li-A cm. Juglans regia L. var. orientis (Dode) Kitam. /. ones- 

 wide, abrupdy acute to acuminate, appressed-serrulate, mi- tis Dode; /. regia var. sinensis sensu auct. Japon., non DC. 



nutely stellate-pubescent above while young, rather densely Chosen-gurumi. A widely cultivated Chinese tree with 



stellate-pubescent beneath, sessile and obliquely truncate at glabrous leaves and branchlets, the leaflets 3-9, obtuse, entire 



base; petioles and rachis densely glandular; staminate aments except in the young tree; nut relatively thin-shelled. 



10-30 cm. long; pistillate aments 10- to 20-flowered, peduncu- Juglans avellana Dode and Juglans notha Rehd. are al- 



late, densely brown-pubescent with crisped hairs; nut pubes- leged hybrids of /. ailanthifolia Carr. X /. regia var. orientis 



cent, with a hard shell, broadly ovoid to nearly globose, 2.5- (Dode) Kitam. 



3.5 cm. long, mucronate, rugose, with raised sutures. May. 



Hokkaido, Honshu, Shikoku, Kyushu; very variable. 



Fam. 65. BETULACEAE Kaba-noki Ka Birch Family 



Deciduous trees or shrubs; leaves alternate, toothed, simple, the stipules usually caducous; staminate aments pendulous, 

 elongate, the flowers 1-3 in axils of scales, the perianth 2- to 4-lobed, sometimes absent; stamens 2-15, the filaments free, the 

 anther-locules distinct or connate; pistillate aments erect or pendulous, elongate or short, the flowers composed of a single 2- 

 locular ovary; tepals present or absent; styles 2 or sohtary and deeply bifid; ovules 1 or 2 in each locule, anatropous; fruit a nut, 

 sometimes winged; endosperm absent; cotyledons fleshy. About 7 genera, with about 100 species, chiefly in the N. Hemis- 

 phere, usually flowering in early spring. 



lA. Staminate flowers solitary on each scale, without perianth; pistillate flowers with perianth; nut attached to a leaflike bract. 

 2 A. Staminate flowers without bracteole; pistillate flowers in spikelike aments; fruit small, subtended by a large bract. 



3A. Bract of the nut flat, toothed or incised 1. Carpinus 



3B. Bract of the nut connate at base, forming a wbe 2. Ostrya 



2B. Staminate flowers 2-bracteolate; pistillate flowers 2-4, capitate; nut large, enveloped by a large foliaceous involucre 3. Corylus 



IB. Staminate flowers 3-6 on each scale, with a perianth; pistillate flowers without a perianth; nut small, on inner side of closely im- 

 bricated bracts or scales, sometimes winged on margin. 



4A. Stamens 2, the filaments bifid; scales of pistillate aments deciduous when mature 4. Betula 



4B. Stamens 4, the filaments not lobed; scales persistent 5. Alnus 



