240 HORNBEAM: ELM 



Venation strict-pinnate, midrib strong to the middle 

 giving off on each side 10 15 sharp secondaries, straight 

 or the lowermost somewhat divergent to the bi-serrate 

 margin, each ending in a tooth, and alternate or the lowest 

 opposite. Tertiaries not looped, very fine and much ana- 

 stomosed : the outer at acute, the inner at 90 or more 

 obtuse angles: those from the midrib at about 90 or more. 

 Each pair of secondaries distant about -^ of the length of 

 the midrib, the lowest much shorter than those in the 

 middle of the leaf, and almost devoid of conspicuous outer 

 nerves, but with a few weak ones. Leaf-base equal and 

 not cordate. Angle between secondaries to primaries 

 35 45. Secondary segments narrow, the middle nearly 

 linear. Tertiaries connecting. Network well developed, 

 meshes rather loose and rounded. 



U [U Young leaves conduplicate. 



Leaves more or less ovate, not more 

 than 6 10 cm. long, at most pubescent 

 beneath, apex acute or slightly acumi- 

 nate; petiole relatively long. 



Ulmus campestris, Sm. Elm. Tall tree, twigs often 

 with corky ridges. Leaves about 6 10 cm. long (2 10 

 x 2 5), lanceolate to broad cordate, ovate, or elliptic, 

 acute or acuminate, usually very oblique at the base. 

 Obtusely bi-serrate, the main teeth curved forwards ; 

 coarse, nearly smooth above, firm, with tufts of hairs in 

 the angles of the veins below, not glandular. Petiole 

 short, 4 10 mm. and smooth or nearly so. Stipules 

 caducous. The leaves are very firm, almost coriaceous. 

 Autumn leaves golden yellow. 



Venation pinnate, the secondaries straight to the bi- 

 serrate margin and ending in the teeth. Tertiaries not 

 looped beneath the margin. Secondaries about 10 12 



