160 



BETULA 



BIARUM 



Regel.). Lvs. broad-ovate, usually truncate at the 

 base. Var. pendula, Hort. Branches slender, dis- 

 tinctly pendulous ; cult, in several different forms, as 

 var. pendula laciniata, Hort., with laciniate Ivs.; a 

 very graceful form (Fig. 234); var. pendula elegans ; 

 var. pendula Youngi, and others. 



(2) pubescens, Ehrh. (B. odordta, Bechst.). Less 

 pendulous or upright, sometimes shrubby ; branchlets 

 usually pubescent, not glandular : Ivs. ovate, pubes- 

 cent beneath, at least when young : cones pendu- 

 lous or erect. The first grows more in dry situations, 

 while the latter is found growing in moist places, 

 often in swamps. To this subspecies belong the follow- 

 ing varieties : Var. excelsa, Regel. (B. excelsa, Ait.). 

 Tree : Ivs. ovate, short petioled, pubescent beneath. 

 Var. pub6scens, Regel. Branches and Ivs. pubescent, 

 at least when young ; Ivs. ovate, acute. Var. urticifo- 

 lia, Spach. Lvs. small, deep green, irregularly in- 

 cised-serrate, unequal at the base. Var. Carpatica, 

 Regel, P6ntica, Dipp., and tortudsa, Regel, are small 

 trees, without any horticultural value. 



CO. Trunk witJi dark bronze-colored bark. 



11. occidentalis, Hook. Small tree, occasionally 40 ft. ; 

 branchlets slender, glandular : Ivs. broadly ovate or 

 nearly orbicular, acute or obtuse, sharply serrate, short- 

 petioled, glabrous or sparsely pubescent at the veins be- 

 neath, 1-2 in. long : cones 1-1/4 in. long ; bracts with 

 erect, oval lobes, the middle one usually longer. North- 

 west Amer., east to Dakota and Nebraska. S.S. 9: 453. 



BB. Wings smaller than the nut: shrubs 1-15 ft.: Ivs. 

 small, short-petioled : cones erect. 



c. Branchlets glandular, not pubescent. 



12. glanduldsa, Michx. Only 1-4 ft. : Ivs. short-peti- 

 oled, rounded or cuneate at the base, orbicular or 

 broadly obovate, obtuse, dentate, glabrous, %-l>2 i n 

 long : cones peduncled, %-%in. long : lobes of bracts 

 nearly equal, slightly spreading. Newfoundland to 

 Alaska, south to Michigan, and in the Rocky Mountains 

 to Colorado. B.B. 1:510. 



cc. Branchlets pubescent or nearly glabrous, not 

 glandular. 



13. pumila, Linn. Usually 2-8 ft., rarely 15 : branch- 

 lets tomentose or pubescent, at least when young : Ivs. 

 orbicular or oval, acute or obtuse, coarsely dentate, pale 

 and glabrous or pubescent beneath, %-2 in. long: cones 

 peduncled, %-l in. long ; lateral lobes of the pubescent 

 bracts spreading, shorter than the middle one. New- 

 foundland to Minn., south to Ohio. B.B. 1:511. Var. 



fastigiata, Hort. (B. humilia 

 fastigiata, Hort.). Of distinct, 

 upright growth. B. pumila x 

 lenta is shown in G.F. 8:245. 



14. nana, Linn. Low, spreading, rarely 4 ft. : Ivs. 

 o-bicular or cuneate-obovate, crenate, rounded at apex, 

 glabrous, %-%hi. long : cones nearly sessile, X-%in. 

 long ; the upper bracts usually entire, the lower ones 



*.__. .r**7^n{F9RS.grn ^ 



234. Cut-leaved Weeping Birch Betula'^albaJ /- 



233. Leaves of Betula alba. Natural size. 



3-lobed. Arctic N.E. Amer., N. Eu., Siberia. B.B. 1:511. 

 A low, graceful shrub for rockeries and rocky slopes. 

 B. alnoldes, Hamilt. (B. cylindrostachya, Wall.). Tree, 50-60 

 ft.: bark brown: Ivs. ovate-oblong, doubly cuspidately serrate: 

 cones racemose. Himal. Tender. B. alpestris, Fries = B. inter- 

 media. B. carpinifolia, Ehrh.= B. lenta. B. corylifblia, Regel. 

 Allied to B. nigra. Lvs. broad elliptic or obovate, coarsely den- 

 tate : cones cylindrical. Japan. B. cylindrostachya. Wall. = 

 B. alnoides. B. Dahurica, Pall. Tree, to 60 ft.: bark brown : 

 Ivs. ovate, pubescent on the veins beneath, 1-2 in. long : cones 

 oblong. Dahur., Manchuria. B. fruticosa, Pall. Shrub, to 15 

 ft.: Ivs. ovate, glabrous at length and usually glandular be- 

 neath, 1-2 in. long. Siber., Manchuria. B. Omelini, Bunge= 

 B. fruticosa. B. grdndis. Schrad.=B. papyrifera. B. grbssa, 

 Sieb. & Zucc. Allied to B. lenta. Lvs. ovate, unequally serrate, 

 %-2 in. long : lobes of bracts rounded. Jap. B. humilia, 

 Schrank. Two to 6 ft.: branchlets glandular : Ivs. K-l%in. 

 long, crenately serrate, glabrous. M. and N. Eu., N. Asia. B. 

 hybrida, Bechst. Natural hybrid of B. pendulaXpubescens. 

 Tree. B. intermedia, Thomas (B. albaXnana). Shrub : Ivs. 

 orbicular or ovate, %-\ in. long, glabrous. N. Eu. B. Med- 

 wedjewi, Regel. Tree, allied to B. Ermani : Ivs. elliptic, 8-11- 

 nerved : cones cylindrical. Trans-Caucasia. Gt. 36, p. 384. 

 B. Raddedna, Trautv. Allied to B. fruticosa. Tree : Ivs. small, 

 ovate, pubescent on the veins beneath : cones oblong. Cauca- 

 sus. Gt. 36, p. 384. B. ulmifblia, Sieb. & Zucc. 

 Tree: Ivs. ovate, doubly serrate, with 10-14 pairs 

 of veins : bracts of cone with linear oblong 

 lobes. Jap. B.Youngi pendula, Hort. = B. alba, 

 var. pendula Youngi. ALFRED REHDER. 



BIARUM (old and obscure name). 

 Aroldece. Dwarf, tuberous perennials of 

 the same tribe with our native jack-in- 

 the-pulpit. They are hardy in England, 

 but probably are suitable only for pot-cul- 

 ture in the northern U. S. They have a 

 spathe which is tubular at the base, mostly 

 with a long limb, and usually a long tail- 

 like spadix. They grow a few'inches high. 

 Odd. Little known in America. 



tenuifdlium, Schott (Arum tenuifolium, 

 Linn.). Lvs. linear-lanceolate or spatu- 

 late, appearing after the fls. decay: spathe 

 long-acuminate, at length recurved and 

 twisted spirally, about 10 in. long, out- 

 side green, streaked purple ; inside dull 

 purple, spotted ; margins wavy : spadix 

 15 in. long. Spain. B.M. 2282. 



Pyr&mi^Eug.d'schantmPyrdmi, Schott). 

 Lvs. oblong above the middle, narrowing 

 abruptly to a very long petiole, resembling 



