1922] REHDER, NEW SPECIES, VARIETIES AND COMBINATIONS 217 



Acer Buergerianum Miq. var. trinerve, var. nov. — A. trinerve Hort. apud 

 Dippel, Handb. Laubholzk. n. 428, fig. 200 (1892), excl. syn. A. pycnanthum 

 K. Koch.— Pax in Bot. Jahrb. xvi. 393 (1982); in Engler, Pflanzenr. 

 iv-163, 12 (1902), in part— Koehne, Deutsch. Dendr. 376 (1893).— A. 

 trifidum Hort. angl. ex Dippel, Handb. Laubholzk. n. 428 (1892), as synon. 



This form differs from the type in its more deeply 3-lobed leaves, 

 broader and often rounded or almost truncate at the base and with the 

 lobes more strongly and unequally serrate, placed near or below the middle 

 and spreading ,while in typical A. Buergerianum the lobes are placed above 

 the middle and point more or less distinctly forward and the margin of 

 the leaf is usually entire or nearly entire. Occasionally one finds, however, 

 on specimens of typical A. Buergerianum, e. g. on F. N. Meyer's No. 

 1427, collected June 4, 1915 near Nanking (herb. Arnold Arb.), leaves 

 which agree exactly with those of the variety. I have seen neither flowers 

 nor fruit of this form which is apparently a juvenile form of typical A. 

 Buergerianum as suggested already by Koehne, Pax and Spaeth (in 

 Mitteil. Deutsch Dendr. Ges. 1896, 25). Under cultivation it seems to 

 retain its juvenile character and it is therefore advisable to distinguish 

 it by a definite name from the type. 



In the Herbarium of this Arboretum there is a specimen collected by 

 G. Nicholson in 1880 in the Kew Arboretum and labelled "A. trinervum 

 Sieb." w T hich seems to show that this form was originally introduced by 



Siebold. 



Acer Opalus var. tomentosum, comb. nov. — A. neapolitanum Tenore, 

 Fl. Napol. ii. 372, t. 100 (1820); Mem. sugli Acere, 13, t. 4 (1846).— 

 A. opulifolium var. Y tomentosum Tausch in Flora, xn. 549(1829). — Koch, 

 Syn. Fl. Germ. 136 (1837), excl. "(£) lobis obtusis." — A. obtusatum var. 

 neapolitanum Don, Gen. Syst.i. 649 (1831). — Pax in Bot. Jahrb. vn. 223 

 (1886), as subspec; in Engler, Pflanzenr. iv-163,58 (1902).— A Opalus var. 

 neapolitanum Henry in Elwes & Henry, Trees Gt. Brit. Irel. in. 664, t. 



106, fig. 15 (1908). 



The oldest varietal name applicable to A. neapolitanum Tenore is that 



given by Tausch who, though he refers A. neapolitanum as well as A. 



obtusatum Kitaibel to his variety tomentosum considers A. neapolitanum 



the type of his variety, as he enumerates Tenore 's species as (») 



lobis acutis" and A. obtusatum Kitaibel as "((1) lobis obtusis." 



Therefore there can be no doubt that if these two species are considered 



two distinct varieties the varietal name tomentosum has to be applied to 



A. neapolitanum, w r hile A. obtusatum becomes A. opalus var. obtusatum 



Henry in Elwes & Henry, Trees Gt. Brit. Irel. in. 663 (1908). 



Acer Hersii (Sect. Macranthae), sp. nov. 



Arbor gracilis ad 8 m. alta; ramuli ab initio glabri, virides vel an no t in i 

 et biennes lutescentes, nitiduli, vetustiores longitudinaliter albo-striati; 

 gemmae stipitatae, perulis 2 exterioribus valvatis obtectae, perulis 2 



