PLATANACE^. 8ILVA OF NORTH AMERICA. 



107 



PLATANUS WRIGHTII. 



Sycamore. 



Leaves deeply 3 to 7-lobed, the lobes elongated, slender, entire or rarely remotely 

 dentate, usually deeply cordate or rarely wedge-shaped at the base. Fruit racemose- 



Platanus Wrightii, Watson, Proc. Am. Acad. x. 349 Platanus Mexicana, Torrey, Emory's Rep. 151 (not Mori- 

 (1875). — Rusby, Bull. Torrey Bot. Club, ix. 54. — Sar- cand) (1848). 



gentj Forest Trees N. Am. lOth Census U. S. ix. 130. — Platanus racemosa, Watson, PL Wheeler, 16 (not Nuttall) 

 Coulter, Contrib. U. S. Nat. Herb. ii. 410 (Man. PI. W. (1874). — Rothrock, Wheeler's Rep. vi. 239. 



Texas) • 



A tree^ often sixty to eighty feet in height, with a straight trunk four or five feet in diameter at 

 the base, gradually tapering and free from branches for twenty or thirty feet, or with a trunk dividing 

 just above the surface of the ground into two or three large stems, usually more or less reclining, and 

 often nearly prostrate for fifteen or twenty feet, and with thick contorted branches ; of these the lowest 

 frequently grow almost at right angles to the trunk, and are fifty or sixty feet in length, while the 

 upper are usually erect at first, and then spread into a broad open handsome head. The base of the 

 trunk is covered with dark bark three or four inches thick, deeply and irregularly divided into 

 broad ridges, and covered on the surface with small appressed scales ; ten or fifteen feet above the 

 ground it grows thinner, separating into larger scales, and gradually passes into the bark of the upper 

 trunk and branches, which is smooth, much thinner, and creamy white faintly tinged with green. The 

 branchlets are slender, and are coated at first with thick pale tomentum, which soon begins to disappear ; 

 during their first winter they are glabrous or slightly puberulous, marked with minute scattered lenti- 

 cels, and light brown tinged with red, or ashy gray, and gradually grow darker during their second and 

 third years. The leaves are divided by narrow sinuses to below the middle, and sometimes nearly to 

 the centre into three to seven, but usually into five, elongated acute lobes, which are entire, or dentate 

 with callous-tipped teeth, or occasionally are furnished with one or two acuminate lateral lobes ; they 

 are sometimes deeply cordate by the downward projection of the lower lobes or are often truncate or 

 wedge-shaped at the base ; they are six to eight inches in length and breadth, thin and firm in texture, 

 light green and glabrous above and coated with pale pubescence below, with narrow ribs and primary 

 veins connected by rather conspicuous reticulate veinlets, and stout glabrous or puberulous petioles an 

 inch and a half to three inches long. The peduncles are clothed with thick white tomentum, and bear 

 two to four heads of flowers. The heads of fruit hang on slender glabrous stems six to eight inches in 

 length, and are about three quarters of an inch in diameter. The akenes are glabrous, about one 

 quarter of an inch long and truncate at the apex. 



Platanus Wrlghtll inhabits the banks of streams in the mountain canons of southwestern New 

 Mexico, southern Arizona, and Sonora ; on all the mountain ranges in New Mexico and Arizona, south 

 of the high Colorado plateau, it is the largest and one of the most abundant of the deciduous-leaved 

 trees, extending from the mouths of the canons up to elevations of from five to six thousand feet above 

 the level of the sea. 



The specific gravity of the absolutely dry wood is 0.4736, a cubic foot weighing 29.51 pounds. 



Platanus Wrightii was discovered in 1851 by Mr. Charles Wright^ in southern Arizona durin 



t> 



1 See i. 94. 



