264 BETULA BIGELOWIA 



is easily distinguished from B. pubescens by the warts on the young branchlets 

 and by the absence of down on all the younger vegetative parts. In the latter 

 respect it differs from all the other cultivated birches except B. populifolia. 

 (For timber value, etc., see PUBESCENS.) 



Var. DALECARLICA, LinncEUs fit. (B. laciniata, Wahlenberg). Swedish 

 birch. A very distinct form, the leaves being lobed to within J to J in. of 

 the midrib, the lobes themselves lanceolate, coarsely toothed, and with 

 long, slender points ; leaf-stalks from i to if ins. long. Branches and leaves 

 pendulous, and the whole tree very elegant. Found wild in Sweden. 



Var. DENTATA VISCOSA. A bushy, small tree of close, twiggy habit ; 

 branchlets and leaves very viscid ; leaves closely set on the twig, f to ij ins. 

 long, coarsely double-toothed or even small-lobed ; leaf-stalks \ in. long. 



Var. FASTIGIATA, Scheele. Branches erect-growing ; the tree being of 

 columnar habit, and resembling a Lombardy poplar. 



Var. OYCOWIENSIS, Regel. A shrubby form. Leaves mostly diamond- 

 shaped and smaller than in the type ; found wild in N.E. Hungary. 



Var. PENDULA YOUNGI. Young's weeping birch. An extremely elegant 

 tree, suitable for small gardens. The branches are slender and perfectly 

 pendulous. This is the best of several weeping forms. 



Var. PURPUREA. Purple birch. Leaves purple. 



B. WlLSONl, Bean. WILSON'S BlRCH. 



A deciduous shrub, 6 to 10 ft. high, its lower branches prostrate; branchlets 

 thickly clothed the first season with forward-pointing, somewhat appressed, 

 pale brown hairs, glabrous and slightly warted the second season. Stipule's 

 triangular-ovate, silky. Leaves ovate, pointed, rounded or wedge-shaped at 

 the base, irregularly, often doubly, toothed; f to if ins. long, f to I in. wide; 

 veins deeply sunken and forming parallel grooves above, prominent beneath, 

 in twelve to twenty-two pairs; dark green, becoming smooth except on the 

 hairy veins above, clothed beneath with long, brown, silky hairs, especially on 

 the veins and midrib; leaf-stalk ^ to J in. long, silky. Female catkins f in. 

 long; scales three-lobed, ^ in. long, the central lobe twice or more than twice 

 as long as the rounded side-lobes, ciliate. Nutlet fa in. diameter, ovate- 

 orbicular, the wing narrow, ciliate towards the end. Male catkins \ in. long. 



Native of W. China at altitudes of 7000 to 9000 feet. Introduced by Wilson 

 in 1909, who describes it as often hanging down over cliffs. It is very distinct 

 from other dwarf birches in its silky-hairy leaves with numerous veins. 

 (Wilson, No. 1140.) 



BIGELOWIA GRAVEOLENS, A. Gray. COMPOSITE. 



(Bot. Mag., t. 8155.) 



An evergreen shrub, 6 to 8 ft. high, much branched ; branches erect, 

 and white when young. Leaves alternate, crowded on the branch, linear, 

 T to 3 ins. long, \ in. wide or less, long-pointed, smooth. Flower-heads 

 bright yellow, very numerous, forming flattish corymbs i to 4 ins. across ; 

 each head is composed of about five florets, each of which is very slender, 

 tubular, J in. long, the pointed teeth of the corolla erect, the base slightly 

 downy. When crushed the plant emits a not unpleasant, somewhat 

 pungent odour. 



Native of Western N. America, inhabiting dry situations. It is not 

 hardy in the open at Kew, but thrives remarkably well on a south wall, 



