634 T^h^ Trees of Great Britain and Ireland 



A bushy tree, occasionally 30 feet high. According to Loudon,^ introduced 

 in 1756, and common in his day in ornamental plantations, one tree at Croome, 

 Worcestershire, being reported as 40 feet high. This tree, which was 

 probably incorrectly named, no longer exists. This maple * is extremely rare at 

 the present day, and small specimens at Kew have a miserable appearance. 



III. Leaves five-lobed, the basal lobes very small, obscure or obsolete in some of 



the leaves. ^ 



* Leaves quite glabrous beneath, 



16. Acer coriaceuin, Tausch. Hybrid between A. Pseudoplatanus and A. 

 mofispessulanum. 

 Leaves 2^ inches long, 3 inches wide, coriaceous, pale beneath, often deeply 

 cordate, slightly crenulate in margin ; lobes broadly ovate, acute or obtuse. 

 A small tree, rarely seen except in botanical gardens. 

 ~~" 17. Acer glabrum, Torrey. Western North America. 



Leaves 3 inches long and wide, membranous, dark-green and shining above, 

 pale beneath, bi-serrate ; lobes acuminate ; sinuses very acute at their base ; 

 petiole without latex. 



A small tree, young specimens of which are thriving at Kew. In the wild 

 state the leaves are extraordinarily variable, being often tri-partite or tri- 

 foliolate. It is readily distinguished by its perfectly glabrous thin leaves. 



** Leaves glabrous, except for slight pubescence on the nerves at the base. 



18. Acer rotundilobum, von Schwerin.* Hybrid between^. Opalus, var. obtusatum, 



and A. monspessulanum. 



Leaves 3^ inches long and broad, pale beneath, slightly crenate in margin ; 

 lobes short, broadly ovate, cuspidate ; sinuses rounded at their base ; petiole 

 without latex. 



This species, which has leaves thinner in texture and much more glabrous 

 than Acer Opalus, is represented at Kew by a fast-growing young specimen, 

 obtained from Simon Louis of Metz. 



19. Acer hybridum, Spach. Hybrid between A. Pseudoplatanus and A. Opalus. 



Leaves 3^ inches long, 4 inches broad, pale beneath, irregularly and slightly 

 serrate ; lobes broadly ovate, shortly acuminate ; sinuses acute at their base ; 

 petiole with latex. 



There are small trees in the collection at Kew. 



*** Leaves pubescent beneath. 



20. Acer Opalus, Miller, var. obtusattim. Southern Europe, Caucasus, North Africa. 



Leaves (Plate 206, Fig. 16) 3^ inches long, 4 inches wide: under surface 

 pale with the pubescence densest on the nerves ; lobes broadly ovate or 



> Arb. et Frut. Brit. L 407 (1838). 



' Seedlings which I raised in 1905, from seed collected by me near Ottawa in 1904, have grown vigorously at Coles- 

 borne, and are now 3 to 4 feet high. (H. J. E.) 



3 In Mitt. Deut. Dend. Gesell. 1894, p. 76, von Schwerin considers the parents to be A. Opalus, var. obtiuatum, 

 and A. Pscndoflatanus. 



