90 



PLATANACEAE. 



PLATANUS. Sycamore. 

 (Family Platanaceae). 



Trees, at length large and open, 

 with exfoliating bark: deciduous. 

 Twigs moderate, rounded, glab- 

 rous, buff, zig-zag: pith moderate, 

 pale or brownish, rounded, con- 

 tinuous. Buds solitary, rather 

 large, sessile, conical, with a single 

 glossy closed scale, the end-bud 

 lacking. Leaf-scars alternate, 2- 

 ranked, nearly annular and en- 

 circling the buds, somewhat cre- 

 nate and elevated : bundle-traces 5, 

 compound or seemingly 7- 9, large: 

 stipule-scars narrow, encircling 

 the twig. Fruits, in fluffy balls on 

 long stalks, are present in winter. 

 The familiar conical buds of 

 the buttonball or sycamore at- 

 tracted the attention of Malpighi 

 who figured them, and sycamore 

 wood, on plate 9 of his Opera 



Omnia as early as 1687. Each of the three caps within which 

 a bud is enclosed represents a pair of stipules united by their 

 edges. The gum that bathes these caps is the product of a 

 type of secretion-glands known as colleters. 



Winter-character references: P. occidentalis. Blakeslee 

 & Jarvis, 330, 482, pi.; Brendel, pi. 3; Hitchcock (1), 4; (3), 

 17; (4), 138, f. 95-8; Otis, 140; Ward, 1:35, f. 19-20; 118, 

 f. 59;, 214, f. 109; Willkomm, 4, 8, 19, f. 13. P. orientalis. 

 Schneider, f. 107. 



Fruit-ball mostly solitary on the stalk. (1). P. occidentalis. 

 Fruit-balls mostly 2 on the stalk. P. acerifolia. 



Fruit-balls characteristically 3 on the stalk. P. orientalis. 



