28 HOUGH'S AMERICAN WOODS. 



282. NYSSA AQUATICA, MAKSH. 



COTTON GUM. TUPELO GUM. LAKGE TUPELO. 



Ger., Groszer Gummibaum; Fr., Gommier grand; Sp., Tupelo grande. 



SPECIFIC CHARACTERS: Leaves ovate-oblong to oval, mostly rounded or sub- 

 cordate at base, long-acuminate, irregularly angular-dentate or entire, tomentose 

 at firse but finally glabrous dark green above, pale and downy pubescent beneath, 

 5-10 in. long; petioles l 1 /^-2 1 /^ in. long. Floicers appear in March and April, with 

 long slender peduncles from the axils of bud-scales below the new leaves; the 

 staminate in dense capitate clusters, the pistillate solitary; style revolute into a 

 coil. Fruit on slender drooping stems, 2-4 in. long, obovoid, tipped with the 

 remnants of the style, about 1 in. long, dark purple with pale dots, tough skin and 

 narrow obovoid stone, compressed and with about 10 sharp wing-like longitudinal 

 ridges. 



The Cotton Gum is the largest representative of its genus, as it 

 sometimes attains the height of 100 ft. (30 m.), with straight 

 columnar trunk 3 or 4 ft. (1 m.) in diameter above its wide flaring 

 base. This may be of more than double that diameter at the surface 

 of the ground, and is usually hollow. Unlike the horizontal and 

 drooping habit of branching seen in the allied Sour Gum, the Cotton 

 Gum is of quite upright habit of growth and its branches are less 

 numerous than are those of that tree. The bark of trunk is of an 

 ashen gray color and exfoliates in large irregular scales, showing but 

 little tendency to form prominent ridges such as seen in the other 

 species. 



HABITAT. The Atlantic Coast region from the Dismal Swamp in 

 eastern Virginia southward to central Florida and westward into 

 eastern Texas. It also ranges up the Mississippi River valley to 

 southeastern Missouri, and is particularly abundant in the lower 

 Mississippi basin. It inhabits deep swamps and the margins of 

 streams and ponds, where its base is covered with water during a con- 

 siderable portion of the year. In the loose miry soil of these localities 

 the exaggerated width of its base is really necessary to give it the 

 requisite stability. 



PHYSICAL PROPERTIES. Wood quite soft, light, tough, compact, 

 difficult to split, with very small and quite uniformly distributed open 

 ducts and exceedingly fine medullary rays. It is of a light brown 

 color with very abundant buff-white sap-wood. Specific Gravity, 

 0.5194; Percentage of Ash, 0.70; Relative Approximate Fuel Value, 

 0.5158; Coefficient of Elasticity, 51678; Modulus or Rupture, 655; 



