320 QUERCUS 



tree for streets, etc. This oak must not be confounded with the c< Black Jack 

 oak" the Q. nigra of Wangenheim a very different tree. (See Q. mary- 

 landica.) 



Q. OBTUSATA, Humboldt. 



A deciduous tree retaining its leaves well into the New Year, not yet more 

 than 40 ft. high in this country, but said to be a large tree in nature ; young 

 shoots smooth, becoming grey the second year. Leaves of firm, hard texture, 

 strongly ribbed and net-veined beneath ; obovate, tapered at the base, 

 rounded or broadly pointed at the apex, shallowly and unevenly lobed or 

 nearly entire ; 2 to 4^ ins. long, I to 2^ ins. wide ; vivid green above, slightly 

 glaucous beneath, both surfaces without down ; stalk 4 to ^ in. long, smooth. 

 Acorns f in. long, the lower third enclosed in a cup that is downy inside, 

 and has appressed downy scales outside ; acorn stalk \\ to 2 ins. long. 



Native of Mexico ; introduced in 1839 for the Horticultural Society by 

 Hartweg. It is of particular interest as the one Mexican oak really hardy. 

 A tree has stood for many years on an exposed part of the Syon Vista at Kew, 

 slow-growing, but not suffering from cold. 



Q. PALUSTRIS, Muenchhausen. PIN OAK. 



A deciduous tree, 70 to 100 ft. high, forming a dense head of slender 

 branches pendulous at the ends ; young shoots not downy, warted. Leaves 

 3 to 6 ins. long, nearly as wide, obovate, tapered or cut nearly straight across 

 at the base, five- or seven-lobed ; the lobes reaching three-fourths of the 

 way to the midrib, oblong or triangular, unequally toothed near the apex ; 

 both surfaces are glossy green and smooth, except that, in the vein-axils 

 beneath, there are large conspicuous tufts of greyish down ; stalk very slender, 

 up to 2 ins. long. Acorn about \ in. long and broad, flattish at the base, 

 where it is enclosed by a shallow saucer-shaped cup. 



Native of the eastern United States ; introduced to England in 1800. 

 It occasionally bears crops of acorns, which require two seasons to mature. 

 It is one of the very best growers among American oaks cultivated in this 

 country, and is very elegant in its slender branches, especially whilst young 

 or of the middle size. The leaves often turn deep scarlet in autumn, but I 

 do not think it is so effective and reliable in this respect as Q. coccinea ; on 

 the dry soil at Kew it is, at any rate, much inferior. It is frequently confused 

 with Q. coccinea, but Q. palustris is distinguished by its more densely branched 

 graceful head, by the invariable and conspicuous tufts of down beneath the 

 leaf, by the shallower acorn-cup, and by the glabrous winter buds. From 

 rubra it differs in the more deeply divided leaves, polished green on both 

 sides. 



Var. PENDULA. Branches much more drooping than in the type. 



Q. PEDUNCULATA, Ehrhart. COMMON OAK. 



(Q. Robur, Linnceus (in part).) 



A deciduous tree which develops in the open ground a broad, spreading 

 head of rugged branches wider than the tree is high. In such positions, 

 fully grown trees are 60 to 80 ft. high, but where they are growing close 

 together they reach 100 ft. or more in height ; young shoots smooth. Leaves 

 stalkless or shortly stalked, obovate or oblong, ordinarily 2 to 4 ins. long, 

 f to 2^ ins. wide ; the margins cut into three to six rounded lobes ; tapered 

 towards the base, where are two small lobes ; upper surface dark green, 

 lower one greyish, smooth. Acorns f to ij ins. long, one to several on a 



