Trees of Xnr Yorl: Shilr 229 



PLATANACEAE 



Pl:it;iiiiis 0('ci(U'iii;ilis Ij. 



Sycamore, Buttonwood, Plane Tree 



Habit — 'I'lic most iiKissivc tree of (';i.s1('ni North America, commonly 50-100 

 feet ill lioifjlit with a tniiik (lianiotcr of 8-8 feet, under oj)timuiii condi- 

 tions sometimes l.")()-170 feet tall with a trunk diameter of 11 feet. Bole 

 erect or often declined, taperinj^, continuous throufi^h the oblong head or 

 soon breaking up near the ground into several large, massive limbs to 

 form a broad, rounded, irrregular crown. 



Leaves — ^ Alternate. ])roadly ovate or orbicular, 4-7 inches in diameter, 

 ti'uncate, slightly cordate or cuneate at the base, shallowly 3—5 lobed and 

 ]tahna.tely veined, the lobes broad, acuminate, sinuately dentate with 

 remote acuminate teeth, or entire. At maturity the leaves are thin, firm, 

 smooth and ])right green above, paler ajul white-woolly below on the 

 principal veins, borne on stout petioles 1-2*^ inches long. 



Flowers — Appearing on the growth of the season during May when the 

 leaves are about one-fourth gro\m, monoecious, borne in capitate heads. 

 tStaminato heads dark red, al)out V-t of an inch in diameter, borne axillary 

 on long, stout, woolly peduncles. Perianth of 3-5 minute sepals and 

 petals. Htamens 3-6, nearly sessile, with yellowy clavate anthers. Pistil- 

 late heads pale green tinged Avith red, about % of an inch in diameter, 

 borne terminally on long, stout, woolly peduncles. Perianth of 3--6 

 sepals and petals. Pistils as many as the sepals, superior, surrounded 

 by a like number of spatulate staminodia, each consisting of an ovate- 

 oblong ovary surrounded at the base by long pale hairs which persist in 

 fruit, and long, tapering, bright red styles stigmatic along the ventral 

 suture. 



Fruit — A spherical, brown, aggregate head, about 1 inch iji diameter, borne 

 on a long, smooth peduncle 2i^-6 inches long, consisting of many closely- 

 com])acted, clavate, 1 -seeded nutlets, each croA\aied by the remains of the 

 persistent style and furnished with a ring of bristly hairs about the base. 

 The heads mature in the late autumn but persist on the branches into 

 tlie winter and following sjiring. 



Winter characters — Twigs rather stout, smooth, somewhat lustrous, zigzag, 

 enlarged at the nodes and encircled by stipule-scars, dark orange-brown, 

 at length light gray. Pith white and rather broad. Terminal bud absent. 

 Lateral buds divergent, conical, obtuse, lustrous, reddish brown, %-% 

 of an inch long, subpetiolar until leaf-fall. Mature bark at base of 

 trunk thick, dark brown, deeply furrowed with broad ridges which peel 

 off as dark brown scales. On young trunks or large limbs the bark is 

 much thinner and flakes off during the early summer in large plates, 

 exposing a whitish, yellowish, or greenish inner bark. 



Habitat — ^ Thrives best along river banks and on rich, moist bottom-lands 

 but will grow in rather dry soils. Attains its best development in the 

 Ohio and Mississippi River basins. 



Range — Southern Maine Avestward through southern Ontario and Michigan 

 to Minnesota and Nebraska, south to Florida and eastern Texas. Zones 

 A, B and C. 



Uses — A timber species of secondary importance. Wood hard, heav}-, weak, 

 coarse-grained not durable, light broAATi with pale yellowish sapwood. 

 Used for crates, tobacco boxes, butchers' blocks and for interior finish as 

 quartered sycamore. Occasionally planted ornamentally. 



