MONOECIA— POLYANDRIA. Betula. 153 



all botanists devoted to one object, as he was to fruits and seeds, 

 mostly attach too universal and exclusive importance to such 

 parts, in botanical discrimination. A good judge should con- 

 template the whole fructification and habit impartially, learning 

 from thence the limits of a genus, and not making technical 

 characters form the genus, as is now too often done ; witness 

 some able French writers on OrchidecB, and a thousand unlearn- 

 ed ones on every side. Willdenow cannot however pass un- 

 blamed for naming corolla in Castanea, what is evidently as 

 truly a calyx as in his Fagus. Could he really aim at making 

 only a more plausible generic character ? — Dr. Hooker very pro- 

 perly corrects him. 

 The nuts, termed Beech Mast, are the food of hogs, and of va- 

 rious small wild quadrupeds. By pressure they yield a sweet 

 oil, fit for many purposes, but which has, 1 know not why, dis- 

 appointed several speculators who aimed at making it a source 

 of pecuniary advantage. 



444. BETULA. Birch. 



Li?m. Gen. 485. J«ss. 409. Fl.BrAOW. Comp.ed.4. 157. Tottrn. 

 t. 360. Lam. t. 760. Gcertn. t. 90. 



Nat. Ord. see w. 442. 



Harr.Ji. Catkin cylindrical, lax, imbricated all round, with 

 ternate, concave scales ; the middle one largest, ovate. 

 Cor. none. Filani. 10 — 12, shorter than the middle scale, 

 to which they are attached. Anth. roundish, 2-lobed. 



Fert.Jl. Catkin similar, but more dense; scales horizon- 

 tal, peltate, dilated outwards, 3-lobed, 3-flowered. Cor. 

 none. Germ, compressed, bordered, of 2 cells. Styles 

 2, awl-shaped, downy. Stigm. simple. Niit oblong, de- 

 ciduous, winged at each side, of 1 cell, with a solitary 

 kernel. 



Trees or shrubs, very hardy, with round, slender branches ; 

 scattered, stalked, simple, serrated, deciduous leaves-, 

 and a hard, often veiny, tsoood. Bark, in several species, 

 of many fine, soft, membranous layers. 



1. B. alba. Common Birch. /3. Weeping Birch, 



Leaves ovate, acute, somewhat deltoid, unequally serrated, 

 nearly smooth. 



B. alba. Linn.Sp. PI. \3Q3. WUld.v.4.46'2. H. Br. 1012. Engl. 



Bot.v. 31. <. 2198. Hook. Scot. 274. Fl. Da7i. t. 1467. 

 B. n. 1628. Hall. Hist. v. 2. 299. 

 B. pubescens. Ehrh. Arb. 67. PI Off. 338. 



