Modulus of Rupture. 9500 (average of 118 tests by U. S. Forestry Div.).[56] 9200. Remarks. Wood sometimes commercially known as satin walnut and sometimes as star-leaved gum. Large specimens often have hollow butts. [p101] FOOTNOTES [Footnote 55: E. C. Woodward, C. E. Division Engineer Texas & Pacific Ry. reports "gum" ties good after 5 years' service. They hold spikes well.] [Footnote 56: See page 6.] SOUR GUM, BLACK GUM, TUPELO. _Nyssa sylvatica Marsh._ Nomenclature. (Sudworth.) Sour Gum, Black Gum, Tupelo (local and common names). Pepperidge (Vt., Mass., R. I., N. Y., N. J., S. C., Tenn., Mich., Ohio, Ontario). Wild Pear Tree, Yellow Gum Tree (Tenn.). Gum (Md.). Stinkwood (W. Va.). Tupelo Gum (Fla.). Locality. Maine to Florida, westward intermittently to Michigan and Texas. Features of Tree. Forty-five to one hundred feet high, one and six inches to occasionally four feet in diameter. Ovoid, bluish-black, sour fruit, with seed. Horizontal branches, short spur-like lateral branchlets. Color, Appearance, or Grain of Wood. Heartwood light brown or yellow, often nearly white, sapwood hardly distinguishable, fine grain. Structural Qualities of Wood. Heavy, not hard, fibres interlaced, therefore hard to work, strong, tough, checks unless carefully seasoned, not durable in contact with soil. Representative Uses of Wood. Wagon-hubs, rollers, ox-yokes, bowls, and woodenware. Weight of Seasoned Wood in Pounds per Cubic Foot. 39. Modulus of Elasticity. 1,160,000. Modulus of Rupture. 11,800. Remarks. Limited usefulness because difficult to work. Larger specimen in South. Large trees often hollow at butts and sometimes higher. [p102] COTTON GUM, TUPELO GUM, LARGE TUPELO. _Nyssa aquatica Linn._ Nomenclature. (Sudworth.) Cotton Gum, Tupelo Gum, Large Tupelo (local and common names). Sour Gum (Ark., Mo.). Tupelo, Swamp Tupelo (N. C., S. C., La.). Olivetree, Wild Olivetree (Miss., La.). Locality. Virginia and Kentucky, southward. Features of Tree. Sixty to eighty feet high, two to three feet in diameter. Blue oblong fruit one inch or more in length. Color, Appearance, or Grain of Wood. Heartwood light brown, often nearly white, sapwood nearly the same. Structural Qualities of Wood. Light, not strong, soft, compact, difficult to work. Representative Uses of Wood. Turnery, woodenware, roots used as net-floats instead of corks. Weight of Seasoned Wood in Pounds per Cubic Foot. 32. Modulus of Elasticity. 730,000. Modulus of Rupture. 9300. Remarks. Butts of large trees are usually hollow. Parts above are usually sound. [p103] [Illustration: PLATE 22. HOLLY, BOXWOOD, LIGNUMVITÆ (_Ilex_, _Buxus_, etc.). Box Tree (_Buxus sempervirens_). Holly Foliage (_Ilex opaca_). Lignumvitæ Foliage (_G. sanctum_). Dogwood Foliage (_Cornus florida_). Dogwood Bark (_Cornus florida_). Dogwood Wood. Lignumvitæ Wood.]