162 MAHONIA: WALNUT 



Berberis Aquifolium, Ph. Mahonia. Bush with Holly- 

 like aspect. Lower leaflets some distance up the rachis ; 

 all but the terminal one sessile. Ovate, approximate, 

 somewhat cordate at the base, distantly spinescent 

 serrate-dentate, with about 6 10 teeth on each side. 

 Leaves purplish or crimson in winter. The leaf slightly 

 sheathing, and "the tip of the sheath prolonged into minute 

 stipule-like bristle-points (see p. 281). Venation reticu- 

 late or obscurely pinnate-reticulate. 



(ft) Leaves neither hard and polished nor ever- 

 green ; leaflets not spinescent - toothed. 

 Large trees, with stout shoots and broad 

 leaf-scars. 



* Leaflets 5 13 at most, oblong-lanceolate 

 or oval pointed, entire or sinuate, glabrous, 

 coriaceous and tough, fragrant. Twigs 

 smooth : pith chambered. 



Juglans regia, L. Walnut (Figs. 35, 36). Large tree, 

 easily known by its chambered pith from all but a few allied 

 plants. Leaves large, 20 25 cm. long, pubescent when 

 young. Leaflets 7 9 (5 13), opposite, sub-sessile, elliptic 

 or long-ovate; acute or shortly acuminate, entire or sinuate; 

 smooth, usually with a few hairs in the angles of the vena- 

 tion, shining dark green above and paler beneath, somewhat 

 oblique at the base, 610 x 3 7 cm. (515 x 3 9 cm., 

 or even larger on suckers), the terminal one not articulated. 

 Late in opening ; brown in autumn. Fragrant. 



Venation pinnate-looped, with numerous, often 12 14 

 pairs, of strong secondaries, coming off at open angles and 

 nearly straight to the margins, there curving forward and 

 looping into an infra-marginal vein. Tertiaries numerous 

 and strong, coming off from the secondaries at nearly 

 right-angles, and forming distinct cross-ties. 



