rr 



7/ood hard, moderately heavy, strong, verj'- tough, nuch finer 

 grained than the A.-nerican v/hite elm ( ULaus americana L.) and 

 subject to fair polish. Annual rings of growth very narro'.v 

 and often visible only lander a hand lens; inner boundary of 

 annual ring ."aarked by a single interrupted row of pores. 



Pores (transverse section) in early v/ood small ( ,065 mm. 

 in diameter), round or sometimes slightly elongated radially, 

 and closed with tyloses in heartrwcod. Small vessels in late 

 wood arranged chiefly in radial, oblique, semi-circular, or 

 frequently in wavy tangential rows, giving the effect of 

 minute festoons or wavy bands on a smooth surface. Vessel 

 walls (longitudinal section) with niunerous, small, bordered 

 pits, hexagonal in outline; small vessels often with spiral 

 markings. Perforations simple. '7ood fibers 1,319 mm, long, 

 with thick v/alls, small lumina , and fe'>v, very small, oblique, 

 slit-like, simple pits, VVood-parenchyma fibers grouped 

 around vessels and in continuous tangential lines connecting 

 isolated or small groups of vessels in outer portion of 

 late wood, visible only under hand magnifier on smooth 

 transverse section. Pith rays numerous, narrov/, barely vi- 

 sible" under a hand lens, and from 1 to G cells wide and 

 from a few to 25 cells high. 



Distribution^ Common liames and Uses 



She Central American elm was recorded first in 1842, 

 from the forests surrounding the Orizaba Volcano in Mexico, 

 In 1898 it v/as collected in the Dota Mountains of Costa l-ii- 

 ca, and quite recently, in the course of the botanical sur- 

 veys undertaken in Panama by the Smithsonian Institution, 

 it was found to constitute an important element of the fo- 

 rests in the upper Caldera Valley in Chiriqui. Although 

 data are lacking, it is to be supposed that it occurs in 

 the lower mountainous belt, betv/een 1000 and 1300 m, alti- 

 tude, in the whole stretch betv/een the tv/o extreme stations 

 in the State of Vera Cruz to the Korth and in Chiriqui to 

 the South, In Chiriqui, its preferred station seems to be 

 on the slopes nearest to the interoceanic divide, where 

 neither humidity nor dryness are excessive, 



Ulmus mexicana is called ira in Costa Hica, and ceniza 

 or ceniz o in Chiriqui. Ira is probably taken from one of 

 the early Indian languages and is applied also to several 

 representatives of the laurel family. Ceniza is a Spanish 



