4-32 ARBORETUM AND FRUTICETUM. PART III. 



* \.japonicum Thun., with roundish palmate leaves, is a Japan tree, 20 ft. high, with the bark of 

 the branches, and the corollas purple, and the fruit woolly. It is described in Thunberg's Flo) a 

 Jitfwnica, p. Ifil. ; in Dec. Prod., i. p. 595. ; and in Don's Mill., i. p. 6f)0. 



^ A. seplenllobum Thun., with smooth, acuminated, 7-lobed leaves, is a Japan tree, 40ft. high, 

 described by Thunberg, and, after him, by De Candolle and G. Don, as before quoted. 



*jf A. pictum Thun., with smooth, palmate, 7-lobed leaves, is a Japan tree, SO ft. high, with ash- 

 coloured branches, and leaves variegated with white. Described as above. 



^ A. trifidum Than., with undivided and trifid entire leaves, and twigs smooth and purplish, is a 

 Japan tree, 20 ft. high, described in the works quoted. 



* A. truncatum, described in Bunge's List of Plants of the North of China, noticed in p. 176. 



New Sorts from Cross-Fecundation. A, obtusatum has very much the ap- 

 pearance of a hybrid between A. Pseudo-Platanus and A. O'palus ; but, whether 

 this be the case or not, there seems no reason for doubting that cross-fecun- 

 dation might be effected in this genus, as well as it is in various others. The 

 objects ought to be, to get more colour into the flowers, and more red into 

 the leaves. A. monspessulanum, with flowers as red as those of A. rubrum, 

 would be a fine variety. Possibly some of the species, might be fecundated 

 by some species of the genus Negundo, which would lead to great changes in 

 the leaves. As a number of the species of ^ v cer do not flower and perfect 

 seeds, till they become considerable trees, it would be desirable, when experi- 

 ments are to be made by cross-fecundation, and the person wishing to try 

 these experiments possesses only young trees, to graft them with scions 

 from trees which already flower and fruit. In collecting species for this 

 purpose, care must be taken, either to procure plants producing hermaphro- 

 dite flowers, or plants having male and female flowers on the same tree; 

 unless, indeed, advantage is proposed to be taken of the circumstance of the 

 tree being only of one sex, to fecundate its flowers, if female, or pistilliferous, 

 with the male flowers of another species ; or, if staminiferous, to fecundate 

 with them the female flowers of some other kind. We are strongly inclined 

 to believe that some of what are now considered aboriginal species of ^4 v cer 

 are only the result of cross-fecundation, produced by accident ; and hence we 

 anticipate a number of new forms, when the attention of cultivators is power- 

 fully directed to this object. Negundo ybaxinifolium will, in all probability, 

 fecundate, and be fecundated by, acers of different kinds ; and this alone 

 would produce something which would amply repay the curious cultivator. 

 The tree produces flowers at an early age; and, as there are in almost every 

 part of the country abundance of trees of yTcer campestris, and A. Pseudo-Pla- 

 tanus, which flower every year, we would recommend a trial to be made 

 between these sorts without delay. Success may not attend the first trial, 

 but the object ought to be persisted in till some result be obtained. A. cre- 

 ticum, A. monspessulanum, and A. campestre will, doubtless, fertilise together; 

 because, in foliage, in mode of growth, in time of flowering, and in the form 

 of the fruit, they are very much alike ; and something might be done with 

 them with very little trouble. 



Additional Sorts from accidental Forms of Growth. The eagle's claw maple 

 is a well known and very curious variety. Whenever any appearance of 

 the same kind is observed in any of the other species, it ought to be con- 

 tinued by grafting. By carefully looking out for sports from the average 

 forms, we shall probably, at some future day, have weeping maples, as well as 

 the weeping ash ; fastigiate maples, like the Lombardy poplar ; and purple- 

 leaved kinds, like the purple-leaved beech or common hazel. Though scarcely 

 any of the variegated maples now known can be considered as very handsome, 

 yet a new and beautiful variety of them may one day be procured. 



App. iii. Half-hardy Species of P^cer. 



A. palmalum Thun., described p.422., is, in all probability, only half-hardy ; or, at all events, it is 

 safe to treat this, and the other Japan species, and also those from Nepal, when once they are pro- 

 cured, as half-hardy, when in their young state. A. ob!6ngum, described in p. 405. according to Mr. 

 Royle, descends to the lowest level of all the species found in Nepal, and is, therefore, probably the 

 Undercut of those from that part of the world. 



