. leer 



ACERACEAE 



Acer 



aa. 



of each pair of nutlets angled at about 

 90°; wing and nutlet 30-35 mm. long: 

 lvs. 3-lobed, with a few coarse teeth, 

 subcordate at base, pubescent on the 

 nerves beneath: fls. purple: dioecious 



(Sect. Lithocarpa) 9. 



ff. Lvs. undivided or irregularly lobed, ovate or 



elliptic. 



Wings of the samara acutely angled: lvs. 



pubescent along the nerves beneath 



(Sect. Spicata). 



Lf . margins irregularly sharply and doubly 



serrate, 4-10 cm. long, dull green ... 10. 

 Lf. margins entire or irregularly lobed, 

 2-6 cm. long, glossy above, often glau- 

 cous beneath 8. 



Wings of the samara obtusely angled or 

 nearly horizontal: lvs. ovate to oblong, 

 subcordate at base, abruptly pointed 

 at tip, 3-7 cm. long; margins remotely 

 serrate near and below apex or nearly 



entire (Sect. Integrifolium) 11. 



cc. Lvs. 7-9-lobed; segments sharply serrate: wings of 

 the samara obtusely angled (Sect, almata). 

 Petioles and peduncles glabrous or nearly so: ovary 



and lvs. glabrous 12. 



Petioles and peduncles pubescent, at least when 

 young: ovary villous: lvs. silky-hairy when 

 young, deeply divided into 9-11 pinnatisect lobes 13. 



Lvs. 3-7-foliolate: disks of the fls. wanting (Sect. Negundo). 



Lvs. trifoliolate; lfts. entire or remotely serrate: andro- 

 dioecious: fls. in pendulous racemes: brts. pubescent 

 when young 14. 



Lvs. 3-7-foliolate; lfts. coarsely serrate: staminate fls. in 

 corymbose clusters, the pistillate in pendulous racemes: 

 brts. glabrous 15. 



A. sinopurpurascens 



A. ginnala 



A . buergeria num 



A. cordatum 



A. palmatum 



A. japonicum 



f. aconitifolium 



A. henryi 



A. negundo 



1. Acer davidi Franch. ^WiM (Ch'ing Hsia Ma; Green Toad) (R.M. 580). Tree, to 

 15 m.; fls. IV-V; fr. IX. Central China; locally in An., Che., Ki., Ku. Forest. 



2. Acer grosseri Pax ~WMWi (Ko Lo Tsu; Pueraria-net Maple) (R.M. 581). Tree, to 

 20 m.; fls. IV-V; fr. IX. Central China; locally in An., Che., Hup. Forest. 



3. Acer amplum Rehd. (R.M. 570). Tree, to 25m.; fls. IV-V; fr. VIII-IX. Central 

 China; locally in An., Hup., Ki. Forest. 



4. Acer mono Maxim. JLP]U (Wu Chio Feng; Five-angled Maple) (R.M. 569). Tree, 

 to 20m.; fls. IV-V; fr. IX-X. Japan, north China; locally in An., Che., Hun., 

 Hup., Ki., Ku. Woodland. 



Since Thunberg used the name Acer pictum for the plant now known as Kalopanax picius 

 (Thunb.) Nakai in 1783, it cannot be regarded as valid for this species to which he later applied 

 it (Fl. Jap. (1784) 162). 



5. Acer oliverianum Pax (R.M. 577). Tree, to 25 m.; fls. IV-V; fr. few, in corymbs, 



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