232. PLATANUS WRIGHTII ARIZONA SYCAMORE. 29 



GENUS PLATANUS, L. 



Characters as given for the order, this being the only genus. 

 (The name Platanus is from the Greek, -irXarvis, broad, probably in reference to 

 the leaves.) 



232. PLATANUS WRIGHTII, WATS. 

 ARIZONA SYCAMORE. 



Ger., Arizonische Platane ; Fr., Platane d? Arizona ; Sp., Platano 



de Arizona. 



SPECIFIC CHARACTERS: Leaves deeply 3-7-lobed (usually 5-lobed) with narrow 

 pointed sinuses and long acute entire or dentate lobes, varying from heart shaped 

 to cuneate at base, 6-8 in. long and of about the same width, light green and 

 glabrous above, paler and pubescent beneath; petioles stout, 1J-3 in. long. 

 Powers in globular heads arranged in racemes of 2-4 each with whitish tomentose 

 peduncles. Fruit in globular heads about f in. in diameter, with slender glabrous 

 stems 6-8 in. in length, the achenia about \ in. long, glabrous and truncated at 

 apex. 



The specific name, Wrightii, commemorates the discoverer of the species Mr. 

 Charles Wright. 



The Arizona Sycamore attains the height of 70-80 ft. (24 m.) with 

 trunk sometimes 4 or 5 ft. (1.50 m.) in diameter, dividing into a few 

 massive branches and spreading characteristic irregular head with 

 angular branches. The bark near the bases of large trunks is thick, 

 of a grayish brown color, fissured into narrow ridges and exfoliating 

 in rounded or oblong minutely pitted scales. That of young trunks 

 and branches exfoliates in large irregular plate -like scales and patches, 

 leaving a clear creamy white or greenish color beneath which is the 

 color of the smooth upper, branches. 



HABITAT. The Arizona Sycamore marks the banks of streams in 

 the mountain canons of southwestern New Mexico, Arizona south of 

 the Colorado plateau, being in such localities the most conspicuous 

 and characteristic tree up to an altitude of about 6000 ft. 



In these regions of sun-burned rocks and trees of somber foliage the 

 clean white branches and light green foliage of the Sycamores appear 

 in delightful contrast. 



PHYSICAL PROPERTIES. Wood rather light and soft but strong, with 

 quite uniformly distributed open ducts and large conspicuous medullary 

 rays. The sap-wood is of a pinkish cream color near the bark and 

 shades gradually into a light brown heart- wood. Specific Gravity, 

 0.4736; Percentage of Ash, 1.35; Relative Approximate Fuel Value, 

 0.4672; Coefficient of Elasticity, .45614; Modulus of Rupture, 428; 

 Resistance to Longitudinal Pressure, 327; Resistance to Indentation, 

 117; Weight of a Cubic Foot in Pounds, 29.51. 



