175 



BUTTONWOOD. 

 Platanus occidentalis, Linnaeus. 



FAMILY AND GENITS DESCRIPTION— Xlie I'lane Tree family, Platanaceae, comprises only 

 1 genus, ri:itaDus, with about 7 siiecies, 3 vi •.vUich are native to the United States and 1 to 

 Pi'iiu^ylvaDia. In addition to the 1 species native to tUis State, the Old World Plane Tree 

 (Platanus orientalia L.) is very comiuouly planted as a shade tree in the eastern states. 



FORM — fsiially attains a hoipht of 7ii-]2r> ft., but may rfac-h a h.ML'Iit of 1-10-170 ft. with 

 a diameter of 30-11 feet. It is the most massive of the deciduous trees of North America. 

 Trunk Ui^ually branches near the base Into beavy sub-trunks, Vihich subdivide and form a very 

 deep, wide-spreading, rather open, and Irregular crown. ^ 



BARK — On old trunkn rather thick, rigid, roughened by st.sUow Assures separating broad 

 lidges which peel off mtc thin dark brown scales. On youug trcnks and upper parts of old ones 

 it peels oCC spontaneously into large thin plates exposing a whitish, yellowish, or a greenish 

 inner bark. This mottled inner bark is characteristic, but rarely found near the ground. 

 See Fig. 57. 



TWIGS — Rather stout, zigzag, at flrst green and pubescent, later brownish to gray and 

 iimoolli, decurrently ridged, enlarged at the nodes, marked by numerous, small, pale lenticels, 

 fni.irt.led by stipule-scars. Pith wide and white. 



BUDS — Alternate; terminal bud absent; sub-petlolar, surrotisdcd by base of leaf -stalk or leaf- 

 j-<;in^, i-l of an inch long, conical, dull-pointed, very divergent from section of branch above 

 rrid slightly from section below, covered with 3 scales, the outer one of which is sanooth, 

 shining, reddish-brown, the middle green and gumoy. and the Inner pubescent. 



LEAVES — -AUernate. simido, broadly ovate, 3-5-Iobed, toothed on margin, 4-10 inches across, 

 bright green above, jtale green and white woolly below. Petioles about 2 inches long, round, 

 with enhirged hollow bases. Stipnles 1* inches long, conspicuous, encircling twig. 



LEAF-SCARS — Alternate, 2-raiiked, unequal in width, have a wavy outer margin, nearly 

 »-ncircle the buds at enlarged nodes of branches, fcrni an angle of about GO degrees with the 

 section of branch belo-.r, contain 5-10 bundle-scars which are arranged in a curved line and 

 <.f<.-ur singly or in gioJips. 



FLOWERS — Appear m dense heads with the leaves in May. Staminate and pistillate flower 

 heads occur on different stalks. Staminate are nsillary and dark red; pistillate terminal, 

 greenish and often tinged with red. 



FRUIT — Matures in October. Occurs solitary o;- rarely in 2s in brown heads about 1 inch 

 in diameter suppendea from a slender stalk. Heads often persist far into winter and are 

 'oiiipn'.ed of n^uny hairy aclienos at;out rj of an Inch -long. 



■WOOD — Uiffuse-porous; rays conspicuously broad; pores minute; hard, difficult to split, 

 reddish-brow r with light to (yellowish eapwood. Weighs 35.39 lbs. per cubic foot. Used in the 

 manufacture of furniture, interior furnishing, crates, tobacco boxes, and charcoal. 



DISTINGUISHING CHARACTERISTICS — The Buttonwood, also known as Buttonball, Syca- 

 more, and Plane Tree, can readily be distinguished in summer by its massive form, its 

 whitish, yellowish, or greenish bark of the upper branches which at times are covered with 

 large, thin, dark brown scales of outer bark. The large lea\es with their enlarged hollow- 

 based peticlcT and the flowers in the form of noads, are abo characteristic. In winter the 

 massive form and whitewa.-^hed appearance jf ihe upper branches is distinctive. The smooth, 

 reddish, subpetlolar buds covered by a single exposed scale and surrounded by a leaf-scar 

 with 510 btndle-scars will prevent one from confusing it with any other of our native species. 

 The persistent fruit ^vbich usually occurs solitary is readily distinguished from the oriental 

 species which bears it's fruit in clusters of 2-4. 



RANGE — Maine and Oiitarlo south to Florida, west to Minnesota, Nebraska and Texas. 



DISTRIBUTION IN PENNSYLVANIA — Common along streams, especially in the eastern, 

 south^jrn, and central parts of the State. 



HABITAT Prefers mcisl, fertile soil, but will grow in rather dry soil. Best development in 



the moist valleys of the Ohio and Mississippi rivers. 



IMPORTANCE OF THE SPECIES — The wood of this speci«>s is annuaiy becoming of more 

 comiiierelnl importance and hence it should be idanted at least to a limited extent. It may 

 be grown from cuttings or from seed. It is planted sparingly for ornamental purposes but 

 the Oriental Sycamore seems to be preferred Fince it is more attractive and less subject to 

 fungous diseases. 



