PLATANACE^E 347 



3. Platanus Wrightii, Wats. Sycamore. 



Leaves divided by narrow sinuses to below the middle and sometimes nearly to 

 the centre into 3-7 but usually into 3-6 elongated acute lobes entire or dentate, with 

 callous-tipped teeth, or occasionally furnished with 1 or 2 lateral lobes, sometimes 

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

 wedge-shaped at the base, thin and firm in texture, light green and glabrous above, 

 covered below with pale pubescence, 6' -8' long and broad, with slender ribs, and 

 primary veins connected by conspicuous reticulate veinlets; their petioles stout, gla- 

 brous or puberulous, l'-3' long. Flowers : peduncles hoary -tomentose, bearing 14 

 heads of flowers. Fruit: heads on slender glabrous stems 6'-8' long, about ' in 

 diameter; akenes glabrous, \' long, truncate at the apex. 



A tree, often 60-80 high, with a straight trunk 4-5 in diameter, gradually 

 tapering and free of branches for 20-30, or with a trunk divided at the ground 

 into 2 or 3 large stems usually more or less reclining and often nearly prostrate for 



15-20, thick contorted branches, the lowest growing almost at right angles to the 

 trunk and 50-60 long, the upper usually erect at first, finally spreading into a 

 broad open handsome head, and slender branchlets coated at first with thick pale 

 tomentum, becoming glabrous or slightly puberulous during their first winter, 

 marked by minute scattered lenticels, and light brown tinged with red or ashy gray, 

 and gradually darker in their second or third year. Winter-buds hardly more 

 than \' long. Bark at the base of the trunk dark, 3'-4' thick, deeply and irregu- 

 larly divided into broad ridges, and covered on the surface with small appressed 

 scales, thinner and separating into large scales 10-15 above the ground, and gradu- 

 ally passing into the smooth much thinner creamy white bark faintly tinged with 

 green of the upper branches. 



Distribution. Banks of streams in the mountain canons of southwestern New 

 Mexico and southern Arizona; and in Sonora; the largest and one of the most 

 abundant of the deciduous-leaved trees on all the mountain ranges of southern 

 New Mexico and Arizona, extending from the mouths of cailons up to elevations of 

 5000-6000 above the sea. 



