41(J F. Fedde: Morphologie und Systematik der Siphonogamen 1906. [172 



Leaves undivided er 8-lobed, with short entire or sparingly 

 serrate lobes. 

 Leaves membranaceous or chartaceous, green or rarely 

 glaucescent beneath; lobes of almost equal length; 

 wings of the fruit erect or spreading. 



19. Acer Buenjerianum. 

 Leaves coriaceous, glaucous beneath, the middle lobe 

 several times longer than the lateral lobes, wings. 

 of the fruit spreading at a right angle. 



20. Acer PaxiL 

 Leaves undivitled, coriaceous, mostly persistent; inflorescence short-pani- 

 culate; nutles convex. IV. Integrifolia. 



a) Leaves quite entire. 



Leaves distinctly 3-nerved at the rounded base. usually glaucous 

 beneath; inflorescence pubescent. 21. Acer ohlongum. 



Leaves not 3-nerved at the more or less cuneate base. 



Inflorescence pedunculate; leaves green on both surfaces, their 

 petioles short. 

 Leaves distinctly reticulate. 22. Acer laevigatum. 



Leaves not reticulate, caudate; inflorescence purplish. 



23. Acer Fargesi. 



Inflorescence sessile ; leaves green orvglaucescent beneath; their 



petioles siender. 24. Acer lanceolafnm. 



aa) Leaves luore or less serrate or dentate, especially tovvard the 



apex, rounded to cordate at the base. 



Leaves green beneath, cordate at the base, sparingly serrulate. 



25. Acer cordatum^ 



Leaves glaucous beneath, rounded or subcordate at the base,. 



sparingly dentate or sonietimes slightly lobed. 26. Acer discolor. 



Inflorescence andro-monoecious or dioecious (staminate and monoclinous 



or pistillate flowers in different inflorescences), consisting of simple racemes, 



rarely branched neare the base. 



Leaves palraately lobed or undivided, serrate or serrulate; disk intrastaminal. 



Staminate and pistillate inflorescence terminal on leafy branchlets; 



nutlets flattened; winter-buds with two outer valvate scales, 



usually stalked; flowers monoecious (always?;. 



Leaves undivided or but slightly lobed. Y. Indivisicu 



Leaves quite glabrous when young; fruits nearly sessile. 



27. Acer sikkhnense. 



Leaves rufously villous along the veins beneath, at least when. 



young; fruits distinctly stalked. 



Leaves serrulate. not lobed, acuminate rounded or subcordate 



at the base, caudate. 28. Acer Davidi- 



Leaves serrate and slightly lobed, the lobes cordate at the base. 



29. Acer laxiflorum. 

 Leaves palmately 3 or sometimes 6-lobed. VI. Macrantha. 



Leaves roundish-ovate in outline, with short acuminate doubly 

 serrate lobes and shallow sinuses. 

 Leaves rounded or subcordate at the base, 8—12 cm long. 



80. Acer tegmentosum^ 



