16 SYLVICULTURE. 



II. Nuts smaU and flat, in compact catkins (Betulacece). 



(1) Catkin-scales thin, and falling off along with the small seed 



having lateral wings (ripens July-September) . 6. BIRCH. 



(2) Catkin-scales hard, and remaining like a small oval cone after the 



un winged seed is shed 7. ALDER. 



B. FRUIT AN INDEHISCENT SAMARA OR NUT WITH A WING AT ITS UPPER 

 END. 



I. Samara dry, oblong, narrow, thin and flattened, about 1| inch long, 

 light-brown, and arranged in racemes ; each samara is two-celled, 



and each cell 1-seeded 8. ASH. 



II. Samara with 2 (sometimes 3 or 4) seeds, each with long flattened 

 wing above and 1 or 2 seeds in each carpel (MAPLE) : 



(1) Wings at an acute or right angle, and seeds roundish 



9. SYCAMORE OR SCOTS PLANE. 



(2) Wings between a right angle and horizontal, and seeds somewhat 



flattened 10. NORWAY MAPLE. 



(The small FIELD MAPLE has its wings horizontal or forming 

 an obtuse angle, and its seeds roundish. ) 



III. Samara 1-seeded, with flat, thin, smooth, leaf -like membraneous 

 wing extending laterally as well as at top, and cleft at top end, 

 ripening in May or June (ELM) : 



(1) Fruit yellowish and above the middle of the seed- wing, oblong, 



so deeply cleft at top as almost to reach the seed-cavity, and 

 with the hook-like tips overlapping each other considerably 



11. ENGLISH OR SMALL-LEAVED ELM. 



(2) Fruit green and about the middle of the seed-wing, roundish, 



less deeply cleft at top, and hook-like tips only slightly (if at 

 all) overlapping each other . .12. SCOTS OR WTCH ELM. 



C. FRUIT A SMALL, DOWNY, YELLOWISH-GREEN, CORIACEOUS, ROUND 1- OR 

 2 -SEEDED NUT, MORE OR LESS DISTINCTLY RIBBED, AND GROWING 

 IN CORYMBS ATTACHED TO A MEMBRANEOUS BRACT (LlME) : 



1. Corymbs with more than 3 small nuts faintly 5 -ribbed 



13. SMALL-LEAVED LIME. 



2. Corymbs with large bract and not more than 3 nuts of large size, 



and prominently 5-ribbed . . .14. LARGE-LEAVED LIME. 



D. FRUIT A DEHISCENT (SPONTANEOUSLY OPENING) SHORT OR THICK AND 



BROAD CAPSULE, SPLITTING LONGITUDINALLY INTO VALVES. 



1. Capsule round and rough, with soft prickles, about 1| inch broad, 

 and opening in 3 valves to shed 2 to 4 large, glossy brown seeds 



15. HORSE-CHESTNUT. 



